nine of the plays 前面是,说明这是一句话,那就不能有两个主语和谓语,而D) nine of the plays set in Pittsburgh's Hill District 里面有主语和谓语,前面的august Wilson's Pittsburgh cycle consists of ten plays 里面有主语和谓语,所以冲突了,只能用A) nine of which
1 the settings of 后面应该加are 不是is 即使有each one 但看的还是of 前面的东西是单数还是复数
2 feel worn out 感觉精疲力尽。所有形容词都是动词的done形式不是did形式呀