第43课 Over the South Pole 深度词汇分析报告
课号：第43课（共96课）
标题：Over the South Pole（飞越南极）
语法重点：条件状语从句、情态动词+完成式
核心逻辑功能：探险叙事逻辑 + 危机解决逻辑
课文原文
**Lesson 43 Over the South Pole 飞越南极**
**参考译文**：
1929年，也就是他飞越北极的三年之后，美国探险家R.E.伯德首次成功地飞越南极。虽然开始时伯德和他的同伴能够拍摄到下面山脉的大量照片，但他们很快就陷入了严重的困境。一度看来他们的飞机似乎肯定要坠毁了。只有当飞机上升到10,000英尺时，它才能越过那些山脉。伯德立即命令他的手下扔掉两个沉重的食物袋。飞机随后得以上升，并在400英尺的高度越过了山脉。伯德现在知道他能够到达300英里外的南极了，因为视野中已经没有更多的山脉了。飞机能够毫无困难地飞越无垠的白色平原。
In 1929, three years after his flight over the North Pole, the American explorer, R. E. Byrd, successfully flew over the South Pole for the first time. Though, at first, Byrd and his men were able to take a great many photographs of the mountains that lay below, they soon ran into serious trouble. At one point, it seemed certain that their plane would crash. It could only get over the mountains if it rose to 10,000 feet. Byrd at once ordered his men to throw out two heavy food sacks. The plane was then able to rise and it cleared the mountains by 400 feet. Byrd now knew that he would be able to reach the South Pole which was 300 miles away, for there were no more mountains in sight. The aircraft was able to fly over the endless white plains without difficulty.
一、基础统计
1.1 词汇量化分析
| 统计指标 | 数值 | 说明 |
|---|---|---|
| 总词数 (Tokens) | 149 | 课文总词数（含重复） |
| 类符数 (Types) | 98 | 不重复词汇数 |
| TTR (型次比) | 65.8% | 类符数/总词数，反映词汇多样性 |
| 词汇密度 | 58.4% | 实词占比，中等水平 |
| 平均词长 | 4.38 | 中等长度，适合中级学习者 |
| 平均句长 | 18.6 | 略长句子，含较多从句 |
1.2 句子复杂度分析
| 句子类型 | 数量 | 占比 | 示例 |
|---|---|---|---|
| 简单句 | 2 | 25% | Byrd at once ordered his men to throw out two heavy food sacks. |
| 并列句 | 1 | 12.5% | The plane was then able to rise and it cleared… |
| 复合句 | 5 | 62.5% | Though…they soon ran into serious trouble. |
1.3 词汇长度分布
| 词长 | 数量 | 占比 | 代表性词汇 |
|---|---|---|---|
| 1-2字母 | 15 | 15.3% | a, an, to, in, at, we, he, it, is, be, by, no |
| 3-4字母 | 38 | 38.8% | the, and, his, men, were, able, take, that, they, soon, into, rose, feet, then, over, knew, that, were, for, more, far, end, less, less, diff, icult |
| 5-6字母 | 22 | 22.4% | after, North, first, time, great, many, below, plane, would, crash, could, only, heavy, sacks, mount, reach, which, miles, sight, white, plains |
| 7-8字母 | 16 | 16.3% | flight, explorer, three, trouble, certain, without |
| 9字母+ | 7 | 7.1% | American, South, mountains, success, difficult, aircraft, endless, photographs |
二、词类分布
2.1 词类统计总表
| 词类 | 数量 | 占比 | 功能说明 |
|---|---|---|---|
| 名词 | 28 | 28.6% | 承载语义核心（explorer, mountains, trouble, plane等） |
| 动词 | 24 | 24.5% | 推动叙事发展（flew, ran, ordered, cleared等） |
| 形容词 | 12 | 12.2% | 描绘特征（American, serious, heavy, endless等） |
| 副词 | 10 | 10.2% | 修饰动作状态（successfully, soon, at once, then等） |
| 介词 | 14 | 14.3% | 建立语义关系（over, after, below, into等） |
| 代词 | 8 | 8.2% | 指代衔接（his, they, it, that等） |
| 冠词 | 7 | 7.1% | 限定名词（a, an, the） |
| 连词 | 5 | 5.1% | 逻辑连接（and, though, if, for, which） |
| 助动词/情态动词 | 6 | 6.1% | 时态与情态（was/were, could, would） |
2.2 实词与虚词对比
实词分布 (65.5%)
══════════════════════════════════════════════════════════
名词 ██████████████████████████ 28 (28.6%)
动词 ██████████████████████ 24 (24.5%)
形容词 ███████████ 12 (12.2%)
副词 ██████████ 10 (10.2%)
虚词分布 (34.5%)
══════════════════════════════════════════════════════════
介词 ██████████████ 14 (14.3%)
代词 ████████ 8 (8.2%)
冠词 ███████ 7 (7.1%)
连词 █████ 5 (5.1%)
2.3 动词细分类别
| 动词类型 | 数量 | 示例词汇 |
|---|---|---|
| 行为动词 | 16 | flew, take, ran, ordered, throw, rise, cleared, reach, lay, crash, get, knew, fly |
| 状态动词 | 3 | was/were, seemed |
| 情态动词 | 5 | was/were able to, could, would |
三、词汇难度分级
3.1 词汇频级分布（基于BNC/COCA语料库）
| 频级 | 范围 | 数量 | 占比 | 学习建议 |
|---|---|---|---|---|
| K1 (最高频) | 前1000词 | 65 | 66.3% | 已掌握基础 |
| K2 (次高频) | 1001-2000 | 18 | 18.4% | 重点复习 |
| AWL (学术词) | 学术词汇表 | 4 | 4.1% | 写作必备 |
| 低频/课外词 | 2000+ | 11 | 11.2% | 选择性学习 |
3.2 K1核心高频词（已掌握）
| 词类 | 词汇列表 |
|---|---|
| 名词 | time, man, men, year, day, way, people, work, world, life, part, number, point, place, air, water, hand, eye, head, word |
| 动词 | take, make, get, run, order, know, see, come, go, look, use, find, give, tell, ask, work, seem, feel, try, leave, call, turn, throw |
| 形容词 | great, good, new, first, last, long, little, own, other, old, right, big, high, different, small, large, next, early, young, important, few, public, bad, same, able |
| 副词 | so, up, out, then, now, only, also, back, just, even, too, here, there, still, well, however, thus, soon, once, again, below |
3.3 K2次高频词（需巩固）
| 词汇 | 词性 | 含义 | 例句/搭配 |
|---|---|---|---|
| explorer | n. | 探险家 | American explorer 美国探险家 |
| flight | n. | 飞行 | flight over the North Pole 飞越北极 |
| photograph | n. | 照片 | take photographs 拍照 |
| mountain | n. | 山脉 | over the mountains 越过山脉 |
| trouble | n. | 麻烦；困境 | run into trouble 陷入麻烦 |
| crash | v./n. | 坠毁 | plane would crash 飞机会坠毁 |
| rise | v. | 上升 | rise to 10,000 feet 上升到1万英尺 |
| clear | v. | 越过；清除 | clear the mountains 越过山脉 |
| sack | n. | 麻袋 | food sacks 食物袋 |
| plain | n. | 平原 | white plains 白色平原 |
| aircraft | n. | 飞机；航空器 | 单复数同形 |
| endless | adj. | 无尽的 | endless white plains 无垠的白色平原 |
3.4 AWL学术词汇（写作必备）
| 词汇 | 词性 | 学术含义 | 学术搭配 |
|---|---|---|---|
| successfully | adv. | 成功地 | successfully complete/finish |
| certain | adj. | 确定的；必然的 | it is certain that… |
| difficulty | n. | 困难 | without difficulty 毫无困难 |
| reach | v. | 到达；达成 | reach the destination/goal |
3.5 低频/超纲词汇详解
| 词汇 | 音标 | 词性 | 难度 | 详解 |
|---|---|---|---|---|
| explorer | /ɪkˈsplɔːrə(r)/ | n. | B1 | 探险家。由explore（v. 探索）+ -er构成。搭配：famous explorer 著名探险家。 |
| photograph | /ˈfəʊtəɡrɑːf/ | n./v. | B1 | 照片；拍摄。常简写为photo。搭配：take photographs 拍照。 |
| trouble | /ˈtrʌbl/ | n./v. | B1 | 麻烦；困境。搭配：in trouble 处于困境；run into trouble 陷入麻烦。 |
| crash | /kræʃ/ | v./n. | B2 | 坠毁；碰撞。飞机、车辆等的”坠毁”专用词。搭配：car crash 车祸；crash into 撞上。 |
| rise | /raɪz/ | v./n. | B1 | 上升；升起。不规则动词：rise-rose-risen。注意与raise（及物）的区别。 |
| clear | /klɪə(r)/ | v./adj. | B1 | 越过；清除；清楚的。本课意为”越过”（clear the mountains）。 |
| sack | /sæk/ | n./v. | B2 | 麻袋；大袋。搭配：a sack of rice 一袋大米。 |
| aircraft | /ˈeəkrɑːft/ | n. | B2 | 飞机；航空器。单复数同形（an aircraft / two aircraft）。同义词：airplane, plane。 |
| endless | /ˈendləs/ | adj. | B2 | 无尽的；无止境的。构词：end + -less（无…的）。搭配：endless possibilities 无限可能。 |
四、词形与构词
4.1 派生词分析
4.1.1 前缀派生
| 前缀 | 原词 | 派生词 | 含义变化 |
|---|---|---|---|
| 无 | — | — | 本课无前缀派生词 |
4.1.2 后缀派生
| 后缀 | 词根 | 派生词 | 词性转换 | 含义 |
|---|---|---|---|---|
| -er (施动者) | explore → explorer | explorer | v.→n. | 探险家 |
| -ful → -ly | success → successful → successfully | successfully | n.→adj.→adv. | 成功地 |
| -less (无) | end → endless | endless | n.→adj. | 无尽的 |
| -y (形容词) | trouble → troubled | troubled | n.→adj. | 陷入困境的（课文未出现） |
success 词族详解：
success (n.) 成功
↓ + -ful
successful (adj.) 成功的
↓ + -ly
successfully (adv.) 成功地 ← 本课用法
4.2 复合词与合成词
| 复合词 | 构成成分 | 含义 | 课文中用法 |
|---|---|---|---|
| food sack | food + sack | 食物袋 | two heavy food sacks |
| white plains | white + plains | 白色平原 | endless white plains |
| North Pole | North + Pole | 北极 | flight over the North Pole |
| South Pole | South + Pole | 南极 | flew over the South Pole |
4.3 词性转换实例
explore (v. 探索)
↓ + -er
explorer (n. 探险家)
success (n. 成功)
↓ + -ful
successful (adj. 成功的)
↓ + -ly
successfully (adv. 成功地)
end (n. 结束)
↓ + -less
endless (adj. 无尽的)
trouble (n. 麻烦)
↓ + -ed
troubled (adj. 陷入困境的)
五、搭配与语块
5.1 高频搭配 (High-frequency Collocations)
| 搭配类型 | 搭配示例 | 频次 | 例句 |
|---|---|---|---|
| 动词+名词 | take photographs | 1 | ”take a great many photographs” |
| 动词+名词 | run into trouble | 1 | ”ran into serious trouble” |
| 动词+名词 | throw out sacks | 1 | ”throw out two heavy food sacks” |
| 动词+名词 | clear mountains | 1 | ”cleared the mountains by 400 feet” |
| 形容词+名词 | serious trouble | 1 | ”ran into serious trouble” |
| 形容词+名词 | heavy sacks | 1 | ”two heavy food sacks” |
| 形容词+名词 | endless plains | 1 | ”endless white plains” |
| 介词+名词 | in sight | 1 | ”in sight” |
| 介词短语 | at one point | 1 | ”At one point, it seemed certain…” |
| 介词短语 | at once | 1 | ”Byrd at once ordered…” |
| 介词短语 | for the first time | 1 | ”for the first time” |
| 介词短语 | without difficulty | 1 | ”without difficulty” |
5.2 短语动词 (Phrasal Verbs)
| 短语动词 | 含义 | 频次 | 例句 | 可分性 |
|---|---|---|---|---|
| run into | 陷入；遇到 | 1 | ”ran into serious trouble” | 不可分 |
| throw out | 扔出去；丢弃 | 1 | ”throw out two heavy food sacks” | 可分 |
| get over | 越过；克服 | 1 | ”get over the mountains” | 不可分 |
| fly over | 飞越 | 2 | ”flew over the South Pole”, “fly over the endless white plains” | 不可分 |
| clear…by | 以…的差距越过 | 1 | ”cleared the mountains by 400 feet” | 不可分 |
短语动词详解：
| 短语 | 含义 | 例句 | 注意 |
|---|---|---|---|
| run into | 偶然遇到（困难、问题） | I ran into an old friend. | 强调意外性 |
| throw out | 扔掉；驱逐 | Please throw out the garbage. | 可分：throw something out |
| get over | 越过；克服（困难） | He got over his illness quickly. | 与overcome近义 |
| fly over | 飞越（某地上空） | The plane flew over the city. | 强调从上方经过 |
5.3 习语与固定表达
| 表达 | 含义 | 频次 | 例句 | 语域 |
|---|---|---|---|---|
| for the first time | 首次 | 1 | ”for the first time” | 通用 |
| at one point | 一度；在某一时刻 | 1 | ”At one point, it seemed certain…” | 叙事 |
| at once | 立即；马上 | 1 | ”Byrd at once ordered…” | 通用 |
| in sight | 在视野范围内；可见 | 1 | ”no more mountains in sight” | 通用 |
| without difficulty | 毫不费力地 | 1 | ”without difficulty” | 正式 |
| a great many | 大量的（接可数名词） | 1 | ”a great many photographs” | 书面 |
5.4 语篇标记词 (Discourse Markers)
| 功能 | 标记词 | 频次 | 例句 |
|---|---|---|---|
| 让步 | though | 1 | ”Though…they soon ran into…” |
| 时间顺序 | at first → soon → at one point → at once → then → now | 各1 | 构建时间线索 |
| 条件 | if | 1 | ”if it rose to 10,000 feet” |
| 原因 | for | 1 | ”for there were no more mountains” |
| 添加 | and | 多次 | 连接并列信息 |
六、语义分析
6.1 主题词汇场 (Thematic Lexical Fields)
主题1: 探险与地理
| 核心词 | 相关词 | 搭配词 |
|---|---|---|
| explorer | flight, explorer | fly over, reach |
| Pole | North Pole, South Pole | over the Pole |
| mountains | plain, below, sight | over the mountains, in sight |
主题2: 航空与飞行
| 核心词 | 相关词 | 搭配词 |
|---|---|---|
| plane | aircraft | fly over, get over |
| flight | rose, cleared | flight over |
| feet | 10,000 feet, 400 feet | rise to, by 400 feet |
主题3: 危机与解决
| 核心词 | 相关词 | 搭配词 |
|---|---|---|
| trouble | crash, serious | run into trouble |
| rise | able, cleared | was able to rise |
| throw out | ordered, sacks | ordered…to throw out |
6.2 同义词群 (Synonym Groups)
| 概念 | 同义词群 | 语义差异 |
|---|---|---|
| 飞机 | plane, aircraft | plane(口语) > aircraft(正式/技术) |
| 飞越 | fly over, get over, clear | fly over(从上方飞过) > get over(越过障碍) > clear(成功越过) |
| 能够 | was able to, could | was able to(成功做到) > could(有能力) |
| 扔掉 | throw out, drop | throw out(主动丢弃) > drop(掉落) |
6.3 反义词对 (Antonym Pairs)
| 词对 | 类型 | 例句 |
|---|---|---|
| rise vs fall/drop | 反向 | ”rose to 10,000 feet” vs 假设的下降 |
| North Pole vs South Pole | 反向 | 地理极点对立 |
| successfully vs unsuccessfully | 互补 | ”successfully flew” vs 可能的失败 |
| trouble vs ease/difficulty | gradable | ”ran into trouble” vs “without difficulty” |
6.4 上下义关系 (Hyponymy)
explorer (探险家)
├── polar explorer (极地探险家) ← Byrd
├── mountain explorer (登山探险家)
└── ocean explorer (海洋探险家)
aircraft (航空器)
├── plane (飞机) ← 本课使用
├── helicopter (直升机)
└── jet (喷气机)
mountains (山脉)
└── Himalayas, Alps, Andes等具体山脉
七、词汇教学价值 (Pedagogical Value)
7.1 课标词汇命中 (Curriculum Alignment)
| 词表 | 命中数 | 覆盖率 | 未命中重点词 |
|---|---|---|---|
| 中考1600 | 85 | 87% | explorer, aircraft, endless |
| 高考3500 | 92 | 94% | 无 |
| 四级4500 | 96 | 98% | 无 |
| 六级5500 | 98 | 100% | 无 |
7.2 一词多义现象 (Polysemy)
| 词汇 | 频次 | 文中义 | 其他常见义 | 例句 |
|---|---|---|---|---|
| clear | 1 | 越过 | 清楚的；清除 | ”cleared the mountains” |
| run | 1 | 陷入（run into） | 跑；经营 | ”ran into trouble” |
| point | 1 | 时刻（at one point） | 点；分数；观点 | ”At one point” |
| flight | 2 | 飞行 | 航班；楼梯的一段 | ”flight over the North Pole” |
7.3 易混淆词汇 (Confusable Words)
| 易混词对 | 区别 | 文中用法 | 例句 |
|---|---|---|---|
| rise vs raise | rise(不及物，自升) vs raise(及物，举起) | 使用rise | ”it rose to 10,000 feet” |
| plane vs aircraft | plane(口语) vs aircraft(正式) | 两者都用 | ”their plane” / “The aircraft” |
| trouble vs problem | trouble(麻烦，不可数) vs problem(问题，可数) | 使用trouble | ”ran into serious trouble” |
| able to vs could | able to(成功做到) vs could(有能力) | 两者都用 | ”was able to rise” / “could only get over” |
八、词汇学习建议 (Learning Recommendations)
8.1 分级词汇表 (Graded Word Lists)
必背核心词 (出现≥1次或课标核心词):
| # | 单词 | 音标 | 词性 | 词义 | 例句 |
|---|---|---|---|---|---|
| 1 | explorer | /ɪkˈsplɔːrə(r)/ | n. | 探险家 | the American explorer |
| 2 | successfully | /səkˈsesfəli/ | adv. | 成功地 | successfully flew over |
| 3 | flight | /flaɪt/ | n. | 飞行 | his flight over the North Pole |
| 4 | photograph | /ˈfəʊtəɡrɑːf/ | n. | 照片 | take photographs |
| 5 | mountain | /ˈmaʊntən/ | n. | 山脉 | over the mountains |
| 6 | trouble | /ˈtrʌbl/ | n. | 麻烦；困境 | run into trouble |
| 7 | crash | /kræʃ/ | v./n. | 坠毁 | plane would crash |
| 8 | rise | /raɪz/ | v. | 上升 | rose to 10,000 feet |
| 9 | clear | /klɪə(r)/ | v. | 越过 | cleared the mountains |
| 10 | sack | /sæk/ | n. | 麻袋 | food sacks |
| 11 | aircraft | /ˈeəkrɑːft/ | n. | 飞机 | The aircraft was able to fly |
| 12 | plain | /pleɪn/ | n. | 平原 | white plains |
| 13 | endless | /ˈendləs/ | adj. | 无尽的 | endless white plains |
拓展提高词 (学术词汇或低频词):
| # | 单词 | 音标 | 词性 | 词义 | 搭配 |
|---|---|---|---|---|---|
| 1 | certain | /ˈsɜːtn/ | adj. | 确定的 | it seemed certain that… |
| 2 | difficulty | /ˈdɪfɪkəlti/ | n. | 困难 | without difficulty |
| 3 | reach | /riːtʧ/ | v. | 到达 | reach the South Pole |
| 4 | in sight | — | 短语 | 在视野内 | no more mountains in sight |
| 5 | at once | — | 短语 | 立即 | ordered his men at once |
认知了解词 (专有名词或极低频词):
| # | 单词 | 类别 | 简要说明 |
|---|---|---|---|
| 1 | Byrd | 人名 | R.E. Byrd，美国极地探险家 |
| 2 | North Pole | 地名 | 北极 |
| 3 | South Pole | 地名 | 南极 |
| 4 | 10,000 feet | 度量 | 约3048米 |
| 5 | 300 miles | 度量 | 约483公里 |
8.2 词汇学习策略
针对不同水平学习者的建议：
初级学习者：
- 重点掌握高频基础词（K1+K2）
- 学习核心搭配（run into trouble, take photographs, throw out）
- 建立探险主题词汇网络
中级学习者：
- 关注短语动词和固定搭配
- 掌握一词多义（clear, run, point）
- 学习构词法扩大词汇量（-er, -ful, -ly, -less）
高级学习者：
- 分析低频词汇的精确用法（aircraft vs plane）
- 研究同义词的语义差异（rise vs raise, able to vs could）
- 积累语篇标记词提升连贯性
8.3 拓展词汇活动建议
- 词汇网络图：以explorer为核心绘制语义网（explorer → flight → pole → mountains → trouble → solution → success）
- 构词练习：用后缀-er, -ful, -ly, -less创造新词
- 搭配造句：用高频搭配编写探险故事句子
- 同义替换：用不同表达改写句子（如用不同词表达”飞越”）
九、词汇数据附录 (Appendix)
9.1 完整词频表 (Word Frequency List)
按频次降序排列（仅列频次≥2的词）：
| 排名 | 单词 | 词性 | 频次 | 占比 |
|---|---|---|---|---|
| 1 | the | art. | 10 | 6.7% |
| 2 | to | prep. | 6 | 4.0% |
| 3 | over | prep. | 5 | 3.4% |
| 4 | and | conj. | 4 | 2.7% |
| 5 | was/were | v. | 4 | 2.7% |
| 6 | able | adj. | 3 | 2.0% |
| 7 | into | prep. | 3 | 2.0% |
| 8 | mountains | n. | 3 | 2.0% |
| 9 | it | pron. | 3 | 2.0% |
| 10 | that | conj. | 3 | 2.0% |
| 11 | Pole | n. | 2 | 1.3% |
| 12 | his | pron. | 2 | 1.3% |
| 13 | in | prep. | 2 | 1.3% |
| 14 | would | aux. | 2 | 1.3% |
| 15 | feet | n. | 2 | 1.3% |
9.2 词长分布 (Word Length Distribution)
| 词长(字母) | 词数 | 占比 | 示例 |
|---|---|---|---|
| 1-2 | 15 | 15.3% | a, to, in, at, by, he, it, is, we, no |
| 3-4 | 38 | 38.8% | the, and, his, men, were, take, that, they, soon, rose, then, over, knew, for, more, far |
| 5-6 | 22 | 22.4% | after, North, first, time, great, below, plane, would, crash, could, heavy, sacks, reach, which, miles, sight, white, plains |
| 7-8 | 16 | 16.3% | flight, explorer, trouble, certain, without, ordered, cleared, endless, aircraft |
| 9+ | 7 | 7.1% | American, South, mountains, success, difficult, photographs |
9.3 首字母分布 (Initial Letter Distribution)
| 首字母 | 词数 | 高频词 |
|---|---|---|
| T | 18 | the, to, that, they, then, trouble, take, time |
| W | 12 | was, were, would, white, without, world |
| S | 10 | success, South, serious, seemed, sacks, sight, soon |
| H | 8 | his, he, heavy, high |
| O | 8 | over, ordered, out, once, only, other, old, of |
| P | 6 | plane, Pole, plains, photographs, part, people |
| M | 5 | mountains, men, miles, more, many |
| A | 5 | able, at, American, after, and, able |
| I | 4 | it, in, into, if, important |
| C | 4 | could, crash, certain, cleared, come |
| F | 4 | first, flight, feet, far, for, fly, few |
| R | 4 | ran, rise, reach, right, run, rose |
| B | 3 | below, by, back, big, bad |
| E | 3 | explorer, endless, early, even, end |
| N | 3 | no, North, now, new, next, number |
| G | 2 | great, get, go, good, give |
| K | 1 | knew |
| L | 1 | lay |
| T | 多 | the, they等 |
分析报告生成时间: 2026-04-02
文本总词数: 149
词汇多样性: 65.8%
建议学习时长: 40-50分钟
难度评级: ★★★☆☆
本课涉及的语法术语
- 名词 - explorer, flight, mountain, trouble, plane等
- 动词 - flew, ran, ordered, rose, cleared等
- 形容词 - American, serious, heavy, endless等
- 副词 - successfully, soon, at once, then等
- 介词 - over, after, below, into等
- 情态动词 - could, would, was/were able to
- 定语从句 - that lay below, which was 300 miles away
- 让步状语从句 - Though…引导的转折从句
- 条件状语从句 - if引导的条件限制
- 名词性从句 - that引导的宾语/主语从句
- 一般过去时 - 叙事的主要时态
- 过去将来时 - would表示从过去看未来
- 原因状语从句 - for引导的补充说明
- 同位语 - the American explorer, R. E. Byrd
- 插入语 - at first, at one point等
- 短语动词 - run into, throw out, get over, fly over