—You look so worried.What’s the matter?—I don’t know________these boring problems.
It was said ____that was _____ he succeeded in running his business.
The farmers are only allowed to cut _____ trees and cut them _____ for firewood once a year.
. Doctors say _____ good diet is of ______ great benefit to our health.
Mike is a student at a famous university, _______ for a doctor degree.
There is a feeling in me _______ we’ll surely find a cure for Aids.