When he realized the police had seen him, the man _________ the exit as quickly as possible.

Maybe if I _____ science, and not literature then, I would be able to give you more help. [ ]

Parents often ask their kids their Internet friends because the kids may be in danger．

We’ll make a trip to Hainan Island next weekend. Will you go with us—No, I can’t _____ it at present because I have little money.

She’s all alone here, and it seems rather unkind to ________her.