在相同条件下计量器具正反行程在同一点示值上所得之差是（）
A、回程误差
B、倾斜误差
C、位置误差
D、零值误差
参考答案：A
(2013·湖南省部分重点中学5月联考)—What are they up to？It’s so noisy.
—Some students________a party.
A．have had
B．are having
C．had had
D．were having
