—How long do you think it is ________ he arrived here?
—No more than half a year, I believe.
A. when B. that C. before D. since
—How long do you think it is ________ he arrived here?
—No more than half a year, I believe.
A. when B. that C. before D. since
D
与下文的答语相连,完整结构是“从他来之后有半年了”。