要使x7是假分数，x大于或等于7；
要使x8是真分数，x小于或等于7；
所以x只能等于7．
故选：B．
We teach _______English and they teach _______ Chinese. [ ]
A. our friends, us
B. our friends, our
C. our friend, us
D. our friend, our
Windows打开的多个窗口，既可平铺，也可层叠。( )
