2019年mpacc考试英语真题——连词71

{01}She always comes to our help when we get into trouble ________ she is very busy．
A.since
B.once
C.even if
D.so that
解析：
本题选C。
{02}__________ maths can be difficult to learn, it is very useful to develop our thinking．
A.While
B.Since
C.As
D.For
解析：
本题选A。