As we all know, with the development of science and technology, the earth's resources are ________ at an alarming rate, so we should make good use of them.
Although the plan hasn’t been approved______ present, he insists______ carrying it out.
Last Monday, I bought a second-hand computer, ______ was very slow.
The lecture hall______ by Doctor Li in the 1980s can contain at most 6,000 people.
That day, we______ for the train station when Tom fell and hurt his legs badly.
Mr Smith closed all the windows while driving______ he wouldn’t catch a cold.