1 A
hear sb/sth do2 C
so...that...3 D
现在进行时的被动语态4 C
without是介词，后面要加名词或者动名词5 D
be good at加名词/动名词6 B
stop...from..阻止做某事，from是介词，后面加名词或动名词7 D
hear from收到某人来信，而且yesterday是表示过去的，所以用过去时态8 B
would you mind doing9 A
spend 时间 (in) doing10 A
finish doing11 C
help sb do/to do12 C
doing sth. takes sb. ＋时间,做某事花了某人多少时间
