The government hastaken measures to____the high pricesof daily goods to keep the market stable.[ ]

Your sister _________ a lot during these years.—Yes. She _________ three years ago.

Mum．Can we go to the art museum tomorrow—Sure．But first we should find out ．

Jack wasn’t saying anything，but the teacher smiled at him ________ he had done something very clever.(2011·湖南)

Has your friend arrived—Yes . He ________ here for half an hour .