Question

Don’t start reading a book ________ you find that it’s one you can read with ease and understanding.

A．when

B．if

C．unless

D．though

Answer 1

C

根据句子句意和逻辑关系可知：请不要读书除非你觉得你读的书是简单易懂的，由此可知答案为unless，选后可复查，一般情况下unless与if…not意思相当，将if…not代入句子可知unless确实为正解。