大河上测量起点距常用仪器不包括（）。
A.经纬仪
B.六分仪
C.平板仪
D.水准仪
参考答案：D
小威站在平面镜前5米处，能清楚地看到自己在平面镜中的像，这时他与平面镜中像的距离是[ ]
A．5米
B．2.5米
C．6米
D．10米
It took more than twenty years for the great artist _the painting was finished completely.
A．as
B．before
C．after
D．when
