These teams, which _____twenty experienced workers, are working hard here to ___the time they have lost before.

A．are made up of; make up of

B．are made up of; make up for

C．make up; make up for

D．make up for; make up

网上教育的核心是（）

A、在多媒体教室上课

B、无须教材

C、到网上教室上课、在线交流

D、以自学为主、无须考试