—I can never forget the days       we spent together in the summer camp.

—Well, especially the day       it suddenly began to rain in the middle of the night.

A．when; when

B．which; when

C．what; that

D．on which; when

已知圆柱形岩样的高度0.7cm，直径3cm，巴西法试验破坏荷载1200N，其抗拉强度为（）

A.3.64MPa

B.1.82MPa

C.11.43MPa

D.5.71MPa