Pollution is a serious problem. Scientists have to _____ some good ways to save it.A. come up with B. come on C. come out
She often sends ________ to me on her mobile phone.
I have been living in London for more than ten years, so I have ________ good knowledge of this city.
He used to go to work by car. The underline word “used” is pronounced________.
---Your new blouse looks very beautiful. Is it _____silk? ---Yes. It’s _______ Hangzhou.
As we know, zoos provide homes _____many endangered animals.