问题

Study hard, ______ you won’t catch up with your classmates.
A:and
B:or
C:but
D:if;
B:or
C:but
D:if;
正确答案是:
同类题型
When he walks ______ my desk, he often knocks my books off the desk.
Would it be _______ for you to pick me up at four o’clock and take me to the airport
Putting on a happy face not only helps us make friends but also makes us feel better —- _______
f the city ________, which provides a lot of jobopportunities for the local people.