several道英语题,xiexie!

several道英语题,xiexie!
1)We found ______ necessary to protect the environment.
A.itB.thisC.thatD.what
2)Look! Lily with her sister ______ a kite on the playgroud.
A.is flyingB.are flying C.flying D.fly
3)根据句意和括号中的单词提示填空.
Either my parents or I _____(be) free tomorrow.
一定要做对!谢谢谢谢!