求问几道英语竞赛的填空题1．It is popularly believed that the riot began o

求问几道英语竞赛的填空题
1．It is popularly believed that the riot began on the night of Saturday,August 20,when a 400-strong crowd of white men,_____“Teds”,attacked houses occupied by West Indians．
A．they are all B．many of them
C．some were D．most of them belong to
这题答案选B,我怎么读着觉得格外别扭.
2．While those dealt with by the courts were overwhelmingly white ,the large number of black people also arrested and the official _____ there had not been a racial motive ensured a legacy of black mistrust of the Metropolitan police that has never really been eradicated．
A．persistence B．perseverance
C．insistence D．instance
请问是怎么从这4个选项里判断出来的