球点球、任意球、角球、中圈开球时，防守队员必须离球9.15米。
参考答案：对
The most crucial time for project risk assessment is ().
A. when a problem surfaces
B. during the planning phase
C. during the close-out phase
D. after the project schedule has been published
铁路对自行车的规定计价重量为（）kg。
A.20
B.25
C.30
D.40
