They are still very cautious about ______ side effect the new medicine will bring about, although the experts have tried it on about 2,000 patients.

It is not very easy for the Chinese ________ for a visa(签证) to the USA.

e my friend Tom’s friendship very much, but_______ I dislike his selfishness

Nobody believed his reason for being absent from the class ________ he had to meet his uncle at the airport.

the stress of employment, some collegegraduates make a popular choice ____ they will join the army.