I simply couldn’t understand how it that you did so much work within such a short time．
A. came about
B. came back
C. came up
D. came along
网友回答
(答案→)A. came about
B. came back
C. came up
D. came along
解析：考查词组：A．came about发生B．came back回来C．came up想出D．came along一起来，how it came about that….?怎么会…?, 句意：我就是不能理解你怎么在这么短的时间完成这么多的工作。选A。