问题

Nobody can learn English well __________he works hard on it.

A:if
B:unless
C:when
D:but;

正确答案是：

同类题型

can cause high blood pressure and hearing problems.

下列各句中，没有语病的一句是

is the third Sunday of June. Children usually buy gifts for their fathers.

Not until he retired from teaching three years ago _________ having a holiday abroad.

How are you getting on with your business?—I’m glad to say it is _____.