The teacher always tells her students that only if hard achieve success.A. do they work

问题补充：

The teacher always tells her students that only if hard achieve success.

A. do they work, will they

B. do they work, they will

C. they work, will they

D. they work, they will

答案：

A. do they work, will they

B. do they work, they will

(答案→)C. they work, will they

D. they work, they will

解析：考查倒装句：句意：老师总是告诉她的学生,只有努力学习了，他们才能获得成功。Only+if引导的时间状语从句放在句首，从句不用倒装，而后面的主句要倒装，选C。