问题
This exerciseis difficult . [ ]
A: so, that few of us can do
B: so, that few of us can do it
C: too, for anyone of us to do it
D: too, for anyone of us to do
B: so, that few of us can do it
C: too, for anyone of us to do it
D: too, for anyone of us to do
正确答案是：
