Question

The police           the murderer everywhere when he suddenly appeared in a theatre.

A．is searching for	B．were searching for
C．are searching for	D．were searching

Answer 1

B

试题分析：根据when he suddenly appeared in a theatre.表示过去正在进行的动作，故用过去进行时；police一般总看作复数形式，故用were，所以选B。
点评：通过时间状语，上下句意思和具体语境来确定时态。形式为单数，但意义永远为复数这类集合名词包括cattle(牛，牲畜)cattle，people(人)，police(警察)等，其用法特点为：只有单数形式, 但却表示复数意义，用作主语时谓语用复数；不与 a(n) 连用，但可与the连用(连用)。如：People will laugh at you. 人们会笑你的。The police are looking for him. 警察在找他。Many cattle were killed for this. 就因为这个原因宰了不少牲畜。注：表示牲畜的头数，用单位词 head(单复数同形)。如：five head of cattle 5头牛，fifty (head of) cattle 50头牛。