He wrote a letter ______ he explains what had happened in the accident.
__________ the text a second time,the meaning will become clearer to you.
Information technology is taught in most schools,__________we have entered the information society.
Scientists say it may be five or six years __________it is possible to test this medicine on human patients.
Parents should take seriously their children’s requests for sunglasses __________.
—Shall we meet tonight?—Sorry,I’m busy.How about_________day?