–Could you tell me how long __________ the book?--Three days.
问题描述：
–Could you tell me how long __________ the book?--Three days.
A.I can keep B.can I borrow C.I can borrow D.can I keep
这道题我看答案是选A,谁知道为什么呢?
答
正确的答案是 A.I can keep
“可以借多久” 的习惯表达是 “how long can I keep it (for)"
for 可以省略.