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
网友回答
A. when
B. if
(答案→)C. unless
D. though
解析：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。