2019年mpa考试英语真题——连词555

{01}They didn"t discover until they happened to enter the back room ______ someone had stolen the priceless painting.
A.that
B.what
C.which
D.when
解析：
本题选A。

{02We won"t keep winning games _____ we keep playing well.
A.because
B.unless
C.when
D.while
解析：
本题选B。