The left-behind kids(留守儿童)can’t see their parents the parents come back home from work.

If you have any difficulties，please do not________to contact our Customer Service Department.[ ]

It is dangerous footballin the street.

Good morning. I’ve got an appointment with Mr Smithin his office. —Morning.You ________ be Mr Jones. This way, please.

____ the chance, otherwise you’ll regretit.