___________ returning from abroad, he set about setting up a club for young climbers

This is her sweater. Where is __________ I can’t find it.

Are you happy with your grades in the math exam —Not at all. I can’t have _______.

What’s wrong –Some pieces of glasses________ me and my arms just now. .

Do you know _____ by the police last night — Yes, because he spread a rumor(谣言) on Wechat.