下列哪种氨基酸不是L-α-氨基酸?()
A.Leu
B.Gly
C.Val
D.Ala
E.Asp
参考答案:B
解析:
甘氨酸(Gly)的α-碳非手性碳原子,无旋光异构体。
在使用心理测验对应聘者进行评价和筛选时,可选择的策略有()
A.首因策略
B.择优策略
C.淘汰策略
D.晋升策略
E.轮廓匹配策略
I can't figure out _____ it is that makes him so difficult at school. [ ]
A. how
B. what
C. why
D. which