How many lessons do you usually have a day?—Six lessons a day,and each of then____45 minutes

问题描述:

How many lessons do you usually have a day?—Six lessons a day,and each of then____45 minutes
A last B lasts C have D are 为什么要选B

last是持续的意思,也就是一节课持续45分钟.然后each(每节课)要跟动词第三人称单数搭配,所以要加S