同学你好，该知识点来自沪江网校《雅思语法精讲【随到随学班】》的课程，想要更系统的学习，欢迎进入课程学习。不仅可以和更多的同学一起学习，而且还有老师、助教随时的学习指导和知识点解答哦。

同学你好~
A plane crashed down the mountains, but...
down the mountains表达不自然。
修正: 改为in the mountains（更符合英语惯用表达）。

a young woman and her baby daughters were not hurt.
young可省略（非关键信息）
修正: 改为 a woman and her baby daughters—were not hurt（用连字符更紧凑）。

So it was mid-winter, it was extremely cold.
So多余，两短句可合并。
修正: 改为 It was mid-winter and extremely cold.（用 and连接更流畅）。

the young woman put children in case and covered them all clothes she could find out.
① the young woman→ 前文已提，改用 She；② in case应为 in a case（漏冠词）；③ all clothes she could find out表达错误。
修正: 改为 She put the children in a case, covered them with clothes明确动作和介词）。

When planes passing overhead next morning, she had a idea.
① passing时态错误；② a idea应为 an idea。
修正: 改为 When planes were passing overhead the next morning, she had an idea.

She stamped out 'SOS,' on the snow.
标点符号混乱（中文逗号）。
修正: she stamped 'SOS' in the snow.（stamped out 多用于抽象意义，如 stamped out corruption）。

This was just seen by a pilot, who sent a message to the nearest town.
just冗余；to the nearest town 可省略（救援逻辑已隐含）。
修正: 改为This was seen by a pilot who sent a message.

祝同学学习进步~