词汇题；根据句意及汉语提示完成单词。
1．This kind of plant is very ______ (稀少的)．It's difficult to find it.
2．Scientists are doing ______ (研究) on how to clean the polluted river.
3．This ______ (情况) often happens to people who travel by car.
4．I don't think it's right to ______ (杀) animals.
5．Lucy was ______ (发狂的) when she heard Michael Jackson's death.
6．People need to help the animals live in ______ (安宁，和平)．
7．Tell me the ______ (原因) why you were late.
8．If I have ______ (足够的) money, I'll buy a big house.
9．Our ______ (政府) is working hard to save pandas.
10．All of us should love our beautiful ______ (大自然)．