How long is it ______ we last spent the holiday in the country together?
I think he is taking an active part in social work. I agree with you ___________.
It took a long time for the connection between body temperature and illness ___________.
Work gets done __________ when people do it together and the rewards are higher too.
24.—I don’t think I need to buy that toy penguin—it’s for kids.—__________you don’t have kids, buy it anyway because it looks good.
—Have you worked here since you graduated?—No, I ____________at a factory in Beijing for six years.