问几道高考英语选择题1.They chatted --- coffee about their experience a

问几道高考英语选择题
1.They chatted ___ coffee about their experience as volunteers during the charity.
Aover Bon Cto Dwith
为什么选A
2.The price of the flat now is ___ that last year.
A.as twice high as Btwice more expensive than
C.as high as twice Dtwice the amount of
选B为什么不对,price 应该用什么修饰
3.--Where is your assignment?
---_________
A.I had already handed it in
B.It was handed in
C.It had been handed in
D.It has been handed in
为什么选D,其他的为什么不行,如B
4.It was the A/N1H1 eqidemic ____ spread almost throughout the country _ promoted the research and production of the flu vaccine.
A.that...that B.that ...which C.what...that Dthat...what
为什么选A?这句话怎么翻译?