在家庭电路中，控制电灯的开关应该接在火线和灯泡之间还是零线和灯泡之间？为什么？

— What’s the matter with John? He has been sitting there for hours.

— A postcard from his father_______ an attack of home-sickness in him.

A．took up

B．set off

C．brought in

D．built up