脂肪族中含有羧基的一类化合物为()
A.醌
B.鞣质
C.木脂素
D.脂肪酸
E.黄酮
参考答案:D
Do you want _____ to see 'Harry Potter' _____ me? [ ]
A. to go, with
B. to go, and
C. going, with
D. going, and
超高压系统产生的电晕是一种无功功率损耗。()