Chọn đáp án đúng và giải thích tại sao

Chọn đáp án đúng và giải thích tại sao:
1. The United State.......a population of 250.000( has/is/have/are)
2. There......any letters in the mail for you today( isn't/ aren't/ wasn't/ weren't)
3. A large number of student in thí school...... English quite fluently( speaks/ is speaking/ has spoken/ speak)
4. A series of lecture...... being presented at the Central Hall this week ( are/ will be/ has become/ is)
5. Beauty as well as health........ Failed her this term( has/ have/ is/ are)
6. Bread and butter.......what she asks for( is/ are/ will be/ have been)
7. Each student......answered the first three question( has/ have/ have to/ must)
8. The study of these animals.........truly fascinating,and many bookes have been written about them(is/ was/ are/ have been
9. The news.....(are/ is/ be/ were) interesting
10. Lingustic.......(find/ finding/ to find/ finds) out the ways in wich languages work.