I tried phoning her office, but I couldn't ________.(2009·全国Ⅰ)
____ number of students were absent from the meeting and ____ number of them is only about fifty .
As we all know, parents are concerned _____ their children’s study, because it is concerned ____ their future .
So far, he ______ in remembering 2,000 English words.
-----_______in your city now? -----Very hot at noon but very cool at night.
--Do you know our town at all? --No, this is the first time I ______here.