该句两个during连用，文法欠佳
似乎应该是: During the civil rights movement of the 1950s, Arkansas and particularly Little Rock were major battlegrounds for efforts to integrate public schools.
单纯one of结构用单数 One of his 40 students comeS from a single-parent family.
one of带从句 用单用双有争议。最好通过语境判断把哪部分当先行词更合句子逻辑
(但有些句子似乎用单用双会影响句意) One of his 40 students who comE from a single-parent family is a girl named Lucy.
他有40个学生是单亲家庭，Lucy是其中之一。 One of his 40 students who comeS from a single-parent family is a girl named Lucy.
他一共有40个学生，Lucy是单亲家庭(其他学生是不是单亲不知道)
(但如果有实际语境支持，可化解歧义。如即便用单数，读者也知道美国不是只有12个国会大厦) one of America’s 12 state capitols that doest not have a dome
the ONLY one of结构用单数 Lucy is the only one of his students who comeS from a single-parent family.
