下列对应微粒的电子式书写正确的是( )
A.钾离子
B.氦原子He∶
C.氯离子Cl-
D.锂原子·Li∶
答案:B
钾离子:K+;氯离子:;锂原子Li·
描述何首乌药材鉴别特征的术语是()
A、车轮纹
B、方胜纹
C、罗盘纹
D、云锦花纹
When a fire()at the National Exhibition, at least then priceless paintings were completely destroyed.
A.broke off
B.broke out
C.broke down
D.broke up