— The bag is too heavy to carry. What’s in it?— Oh, I_______ it_______ books.
---Excuse me, could you tell me _______________________? --- It will leave at 3:00 p.m.
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.