单词适当形式填空 1.In this factory dirty water must be cleaned before rivers are ( ).(pollution)

单词适当形式填空 1.In this factory dirty water must be cleaned before rivers are ( ).(pollution)
接上：2.The lady always looks at ( ) in the mirror before going out to visit others.(she)
3.The weather in spring here is( ) than in autumn.(change)
4.Air,food and water are ( ) for life.(need)
5.He was surprised to see so many ( )mistakes in her homework.(correct)
6.It’s a ( )to talk with you.(please)急需,效率高,