the police hid behind the tree in order not to be seen by the rubbersa,himb,himselfc,themd,themselves

the police hid behind the tree in order not to be seen by the rubbersa,himb,himselfc,themd,themselves
the police hid behind the tree in order not to be seen by the rubbers
a,him
b,himself
c,them
d,themselves

the police hid behind the tree in order not to be seen by the rubbersa,himb,himselfc,themd,themselves
D
police,family等集体名词作主语：谓语动词取决于强调整体还是个体.
当表示一个整体时,谓语用单数
当表示里面的个体时,谓语用复数
E.g：
The police are searching for him.警方在搜捕他.这里指的是警察的个体,警察们
The family is a big one.这是个大家庭.这里是个整体
The family are watching TV.家里的人在看电视.是强调里面的个体