It is the test system, _____ the teachers, that is to blame for the heavy burden of middle school students nowadays.
________ is to do good all one's life and never do anything bad.
They would have fixed the telephone yesterday _________ it was a holiday.
It's uncertain ________ the experiment is worth doing.
Do you know ________ he expects will give us a talk
He insisted that he ________ in good health and _______ to work there.