Iftheoperation________carefullyprepared,itwouldnothavebeensuccessful.
A、wasnotC
语法题：虚拟语气。
It took me a month to get rid _______ the cough.
Water is composed _______ hydrogen and oxygen.
Charles Smith, ______ was my former teacher, retired last year.
Iftheoperation________carefullyprepared,itwouldnothavebeensuccessful.
It is important to ________ your skin from the harmful strong sunlight.
