2019年mpa考试英语真题——介词和介词短语140

{01}I was to have visited the Palace Museum last week, but something unexpected ________ to my father．
A.had happened
B.happened
C.have happened
D.was happened
解析：
本题选B。
{02}Bakeoff has found animals sometimes try not to hit or bite, especially ________ they are playing with a weaker partner．
A.if
B.before
C.unless
D.when
解析：
本题选D。