The nunther of the students who took part in the competition 500，but only a small number of them chosen。
A was；were B were；was C．were；were D．w；was
The nunther of the students who took part in the competition 500，but only a small number of them chosen。
A was；were B were；was C．were；were D．w；was
A
The nunther of +可数名词复数作主语时，谓语动词用单数形式；a nunther of可数名词复数作主语时，谓语动词用复数形式，所以答案选A。