重点讲解：
1. cling to
紧紧抓住；抱紧；
eg. The birds cling to the wall and nibble at the brickwork.
鸟儿们紧贴在墙上，啄着砖缝。
eg. Some people had to cling to trees as the flash flood bowled them over.
一些人不得不紧紧抱住树干，因为湍急的洪水会把他们冲倒。
2. marvel at
惊讶不已；不胜惊羡；大为赞叹；
eg. Her fellow members marveled at her seemingly infinite energy.
她的同事们对她似乎无穷的精力大为惊叹。
eg. The tourists marvel at the beauty of the lake.
游客们惊叹这条湖的美丽。
3. subject sb. to sth.
使经受；使遭受；
eg. Her conduct subjected her to public ridicule.
她的行为使她受众人嘲笑。
eg. The police subjected him to an inquisition that lasted two hours.
警察对他进行了持续两小时的盘问。