—________ is your ruler?
—It's orange.
A:What
B:How
C:What about
D:What color
— ______is the cap?
— It's 5 yuan.
如果a、b互为倒数,x、y互为相反数,则5(x+y)﹣ab=( )
下面句中有一处错误,请找出来并改正。
Mr Black teaches our English. We all like him.
____