2019年mpa考试英语真题——连词450

{01}It never occurred to humans until the mid-1990s _____ some animals can be cloned.
A.where
B.that
C.when
D.what
解析：
本题选B。

{02}As it reported, it is 100 years _____ Qinghua University was founded.
A.when
B.before
C.after
D.since
解析：
本题选D。