抽样调查的误差可包括（）。
A.系统性误差
B.登记性误差
C.偶然性误差
D.责任性误差
E.技术性误差
参考答案：A, B, C
—My mother is ill, so I'm not going to the park with you.
—_____[ ]
A. It doesn't matter.
B. Don't worry.
C. I'm sorry to hear that.
D. Are you going to look after her?
都一处的烧麦是（）面点的代表品种。
A、京式
B、苏式
C、广式
D、西式
