number of +名词复数
=a lot of =los of+名词复数
the number of+名词复数,但动词用第三人称单数
例句：The number of visitors to Frinley has now increased.（has就是第三人称单数）
Mike is a number of my friends ,he likes eating food
(在这里of后面就要跟名词复数)
1,a namber of 许多,很多,相当于a lot of
There are a namber of ants on the ground.地上有很多蚂蚁
2,the number of ……的数量
The number of the apples is 40 苹果的数量是40