下列有机物分子中，所有的碳原子不可能处于同一平面的是[ ]
A．CH3-CH＝CH-C≡C-CH3
B．
C．
D．
答案：D
The music sounded familiar and it brought the happy days back to me ________ I was a child. [ ]
A. when
B. which
C. who
D. where
智力缺损的IQ值为()
A．小于50
B．小于60
C．小于70
D．小于80
E．小于90
