but you must ( )it ( )( )按时归还？

Question

You can keep the book for two weeks,but you must ( )it ( )( )按时归还

Answer 1

归还：return, 按时：on time
所以：You can keep the book for two weeks, but you must (return) it (on) (time).
你可以保留（持有）这本书两周，但你必须按时归还。

Answer 2

分别填return,on,time
on time按时，准时

Answer 3

return，on time
return，归还；on time，按时。