I had expected to come over to see you last night, but someone ______ and I couldn’t get away.

A．called

B．had called

C．would call

D．would have called

连续输送机械的特点包括（）。

A.可以不间断地搬运货物，即装货、输送、卸货均连续进行，不必因空载回程而引起运货间断

B.沿固定的路线输送货物，动作单一

C.通用性较差

D.大多数不能自行取货