-What do you think of the book

问题描述:

-What do you think of the book
-Oh,excellent.It's worth _____a second time.
1、横线上为什么要填reading 而不填being read?
2、second 前面为什么要用a?

be worth doing,be worth to do,be worthy of (doing)“值得”只有这几种用法
a second time是固定短语,表示“再一次”或“又一次”,"a"是不定贯词,不表特指.