【初二英语】There are lots of robots._____ in f

问题描述:

【初二英语】There are lots of robots._____ in f
【初二英语】There are lots of robots._____ in factories.
A.to work
B.works
C.worked
D.working

D能解释一下吗我也是蒙的,不过应该是这个,正在进行时谢谢,好好学习