—David left,do you know?—No,which team is he now?
In the old days, people lived in caves and they had to make a fire _________themselves warm.
At present, many people would rather ___________ in the country because there is _________ pollution in the city.
---Your 12-year-old son doesn’t know much about shopping online, ________ he? --- ___________, actually shopping online is popular with teenagers these days.
--- I hope Jim won’t mind lending you his new digital camera. --- He ___________. I have already borrowed one from my cousin, David.
---Everybody is playing on the playground. Can I join them , Miss Lin? --- __________________ Not until you have completed the Maths exercises.