21、 ___ that they may gradually reduce the amount of labor by 90 percent.

问题描述:

21、 ___ that they may gradually reduce the amount of labor by 90 percent.
A、So clever are the construction robots
B、So clever the construction robots are
C、Such construction robots are clever
D、Such clever construction robots are

A.
so 放在句首,句子要倒装.so 修饰的是(机器人的)聪明,而不是(聪明的)机器人