问题
选择题
_________ we admit that there are still some problems about NMET, we don't mean that it is of no use.
A．Until
B．While
C．As
D．Unless
答案
答案：B
连词while的意思是“当.……的时候, 虽然”，如：While he loves his students, he is very strict with them. 虽然他爱他的学生, 可是他对他们很严格。