用a number of或the number of填空 1.I have been to Beijing_____times.2._____the students in our school has risen this year.3._____visitors came to our school to attend the international educational conference.

1.a number of 我去过北京很多次。
2.The number of 今年我们学校的学生人数上升了。
3.A number of 许多来访者来我们学校出席国际教育会议。

1.a number of
2.the number of
3.a number of

1.a number of a number of：许多的,我去过北京许多次.
2.the number of the number of：什么都数目,数量（谓语动词用单数）
3.a number of

1.a number of
2.the number of
3.a number of
a number of：许多的
the number of：什么都数目（谓语动词用单数）