治疗亚硝酸盐中毒用（）.
A.维生素A
B.维生素B1
C.维生素B2
D.维生素B12
E.维生素C
参考答案：E
—You should have thanked the hostess before leaving.
—I meant ________.But I couldn't find her when I was leaving.
A．to do
B．to
C．doing
D．doing so
我国新石器文化的晚期代表是（）
A.龙山文化
B.周口店文化
C.半坡文化
D.仰韶文化
