Listen! Someone is knocking _________ the door.[ ]

Could you tell me something about Zheng He?–Sure. He was a Ming Dynasty explorer __ the Chinese people are proud of.

Susan wanted an evening job that would allow her toher lovely daughter during the day.

It’s really nice of you to spend so much time ________ me around the city.

Can you take photos with elephants? —- Certainly. ______ elephant is ______ useful animal. I like them.