2019年mpa考试英语真题——连词457

{01}Most birds find it safe to sleep in the trees, but _____ they have eggs or young chicks, they don"t use a nest.
A.why
B.how
C.unless
D.where
解析：
本题选C。

{02}He is so happy _____ his father has promised to buy him an MP5 player.
A.that
B.while
C.which
D.because
解析：
本题选D。