Tom's mother needed ________ at once, ________ made him worried.
A．operating on; that B．operating on; which
C．operating; that D．being operating; which
Tom's mother needed ________ at once, ________ made him worried.
A．operating on; that B．operating on; which
C．operating; that D．being operating; which
B
operate on 对……动手术，对……起作用，对……产生影响，when 指时间，在定语从句中作时间状语。