下面几道英文题请解答下,并说明理由(急)

下面几道英文题请解答下,并说明理由(急)
(1)He is ____German,while his girlfriend is____French.
(A)a.../ (B)a...an (C)/...an (D)/...a
(2)There____a talk on white pollution given by a scientist on TV tonight.
(A)is going to be (B)will have (C)is going to have (D)was
(3)He wrote____letter to his parents yesterday.
(A)a 1100 words (B)an 1100-word (C)an 1100-word's (D)a 1100 words'
(4)He told me the meeting ____on the afternoon of September 10,2000.
(A)took place (B)held (C)would be held (D)was taken place
(5)The students of Class Three are having a party. I'd like to____them.
(A)enter for (B)join in (C)take part in (D)join
(6)The doctors have done everything they can____the man's life.
(A)save (B)saving (C)to save (D)for saving
(7)Though it was very hot,they____having hot-pot.
(A)weren't used to (B)were used to (C)used to (D)didn't use to
(8)What happened to the villagers____night of March 10?
(A)on (B)at (C)at the (D)on the
(9)During the____May Day holiday,millions of families went sightseeing.
(A)seven days (B)seven-day (C)seven day (D)seven-days
(10)It____Yang Liwei about 21 hours____around the earth 14 times in his spaceship.
(A)took...to travel (B)took...traveing (C)spent...to travel (D)spent... traveling
我要解释~谢谢~