Theboycomplained_______apaininhisstomach.
D
complain of :抱怨,说自己有病。句意:这孩子说他肚子痛。
His intelligence will ________ him to get a scholarship to college.
Thenewdiscovery_______beofgreatservicetomankind.
Iftheoperation________carefullyprepared,itwouldnothavebeensuccessful.