（A number) of these （who) （study) engineering is improving （steadily).A．A numberB．whoC．stu

The number of these families has increased ______ 40 percent in the past ten years.

There is a fall in the number of students who take this major.A.decreaseB.riseC.topD.incr

The number of these families has increased by 40 percent in the past ten years.A.在过

Why people who deal with a lot of numbers will be happy to use Macintosh？A.It is easy

The number of the United States citizens who are

People who have held these positions of authority