问题

Unlike watching TV, reading is a highly active process _______ it requires attention as well as memory and imagination

A:until
B:but
C:unless
D:for

正确答案是：

同类题型

It seems to some experts that there are only three commonly-used vedio websites in this area: 56.com, Youku.com, Tudou.com and they_______ 90% of the market.(成都市)

29．—- I wonder how much you charge for your services.—- The first two are free ____ the third costs $30

Responsibility is one of the top qualitiesparents want their children to have when they _______

Excuse me, would you please tell me ________?[ ]

________— S-U-E, Sue.