Sarah decides to move to Hainan because shethinks that the air there is much fresher than ___ here.

Mother asked the youngest kid _____________ with his toy car.

What a nice day! We should go sightseeing ________ watchingTV in the hotel.

Due to the widespread ________ of this medical technology, more diseases can be discovered and treated at an early stage.

Was it in the library ________he often went to do some reading ________he met the pretty girl