2019年mpa考试英语真题——形容词518

{01}When you go out for a picnic, you must ________ snakes in the bushes.
A.be careful
B.look out
C.watch out for
D.take care of
解析：
本题选C。
{02}No one has yet succeeded in explaining the ________ of how life began.
A.reason
B.puzzle
C.problem
D.cause
解析：the reason for sth./the cause of sth.表示“（事情的）起因，缘由”。
本题选D。
{03}At first, everyone listened attentively, but ______ some people became restless and a couple of them began to leave．
A.in the end
B.by the end
C.at the end
D.towards the end
解析：
本题选C。