I have trouble _____this problem. 答案是working out 为啥不是solving How long----- the book b
问题描述：
I have trouble _____this problem. 答案是working out 为啥不是solving How long----- the book b
1.I have trouble _____this problem. 答案是working out 为啥不是solving2.-How long----- the book be kept?
-For 2 days.
答案是may 为啥
答
solve是解决的意思,work out是解出的意思
be kept是被动语态,be原型,疑问词后为情态动词,may表示可以