在原子壳层模型中,主量子数n=3,轨道量子数1=2的壳层最多可容纳的电子数为()。
A.2
B.3
C.6
D.10
E.18
参考答案:D
甲状旁腺功能亢进病人手术前应将血钙降低至()
A.2.8mmol/L
B.3.0mmol/L
C.3.5mmol/L
D.3.8mmol/L
E.4.0mmol/L
Drunk driving used to occur _______, but now it is under control.
A.frequently
B.generally
C.practically
D.gradually