The city government is planning to build a factory to deal with the industry waste，but when and where to build it________.

A．haven’t been decided　　　

B．aren’t decided

C．hadn’t been decided　　　

D．hasn’t been decided

在发动机起动过程中，电磁开关中的吸引线圈的电流_________，保持线圈的电流_________，同时将点火线圈的_________短路。