a number of意思是“许多，大量”，后接可数名词复数，the end of意思是“...的末端， ...末”，例如：

A number of young men like playing computer games.

There is a store at the end of the street.在这条街的尽头/末端，有一家商店

We will have an exam at the end of this month. 本月末，我们将进行一次考试