I haven’t ____ my father r a long time.

“Did you have any difficulty in yesterday’s homework?”—“No, in fact I found _____.”

You can never imagine the great difficulty I had ______ her QQ number.

Our afternoon class starts _____ 2 p.m., I must come to school before 1:50. [ ]

There is no doubt _____ she will be able to repay the money on time.