布氏硬度压痕中心距试样边缘应不小于压痕直径的()倍。
A.2.5
B.5
C.10
参考答案:A
The science fiction ______ last month and now it is popular with children.
A.came up
B.came by
C.came out
D.came off
雌激素与孕激素的突然增加造成子宫内膜坏死、剥削、出血,以至月经来潮。