四双制度是指（）
A、双人临柜
B、双人守库
C、双人管库
D、双人复核
参考答案：A, B, C
— Who ______ the house in your family?
— My father and mother ______. [ ]
A. clean, clean
B. cleans, clean
C. cleans, do
D. cleans, does
胃C细胞分泌
A．内因子B．促胃液素C．生长抑素D．胃蛋白酶原E．肠抑胃肽
