1. 用方框中所给单词或短语的适当形式填空。

opinion, nervous, look across, thousand, fall away

1. （1） About two students are planting trees because it is Tree Planting Day today.
3. （2） In my , Tom can catch up with others if he works hard.
5. （3） When Sally went into the cave, she felt .
7. （4） The tree and down to the ground，
9. （5） I was one of the wonders of the natural world.