—Recent pressure at work may ______ his behavior.
David said that it was______ his strong interest in literature_____ he chose the course.
The number of the people invited to the meeting ____ about 100, but a number of them ____ late because of the heavy snow.
What great trouble we had _______ where his house was.
Having retired(退休), he ______ the club for old men and plays chess every day there.
The mother asked her son_________.