I can’t find ________ beef in the fridge. Shall I buy some?

I went to Sanya with my family this summer and all of us _____ a good trip.

Our English teacher is often _______ to give a talk on English study. He is popular.

Mr Wang’s never been to Canada , has he?—________. He went there on business last week.

What _____ are you doing ? —I’m looking for my book.[ ]