霍乱病人的剧烈腹泻是由下列哪项引起的（）
A.Ⅰ型毒素
B.菌体抗原
C.Ⅲ型毒素
D.Ⅱ型毒素
E.以上均不是
参考答案：D
房地产需要专业估价的理由有（）。
A.房地产具有独一无二性
B.政府部门要求估价
C.房地产的价值量较大
D.估价人员要求估价
E.房地产交易量小
— It’s already Monday. Sam lost his MP4 last Wednesday and he hasn’t found it.
— Really? Do you mean_?
A．did Sam lose his MP4 five days ago
B．Sam lost his MP4 for five days
C．it’s five days since Sam lost his MP4
D．has Sam lost his MP4 for five days
