矿石的机械强度,又分为()四种机械强度。
A.抗扭
B.抗压
C.抗剪
D.抗弯
E.抗拉
参考答案:B, C, D, E
I music since I was a little girl. However, I never dreamed of working of working with an American student to make music before I took part in a cross- cultural learning project.
A.loved; had
B.have loved; have
C.have loved; had
D.love; have
下列各组物质在溶液中能共存的是 [ ]
A.硝酸钙和碳酸钠
B.氢氧化钠和硝酸钾
C.碳酸氢钠和稀盐酸
D.硫酸钠和氯化钡