现有四块不同坡度的场地供某居住区用地选择，以场地坡度（）较为经济合理。
A.2‰
B.5‰
C.8‰
D.12‰
参考答案：D
— Where is John, do you know?
— He ________ Changsha on business. He ________ in two days. [ ]
A. has been to; will come back
B. has gone to; will be back
C. has been in; would come back
D. has gone to; come back
单位要组织20人支农，你认为该怎样组织这项活动
