以下哪一个实验不属于霍桑实验的内容? ()
A.继电器绕线组实验
B.金属切削实验
C.继电器装配实验
D.照明实验
参考答案:B
The smile on my mother's face showed that she was __________ with me.[ ]
A. sad
B. pleased
C. angry
D. sorry
如果经常发脾气,很可能是缺乏哪种维生素?