the number of people invited___fifty,but a number of them__absent for different reasonsa:were;was b:was;was c:was;were d:were ;were

问题描述:

the number of people invited___fifty,but a number of them__absent for different reasons
a:were;was b:was;was c:was;were d:were ;were

c

the number of people invited是主语,指被邀请的人的人数,所以是个单数,所以第一格用was。
a number of them 指他们中的一些,所以是复数,所以后半句用were,所以选C

C ( the number of ...作主语谓语用单数,a number of .……作主语,谓语用复数