Mr Liu is a very popular doctor, so he is always busy______his work.[ ]

At the last moment, Tom decided toa new character to make the story seem more likely.

Again and again the doctor _____ the crying girl, but he couldn’t find out what was wrong with her.

John wanted to go to Spain, but at last decided _________ Canada.[ ]

Do you know the boy ___ is standing under the tree?– Yes, he is my friend, Peter.