18.A peculiar feature of the embryonic mammalian circulatory system is that in the area of the heart the cells adhere to one another, beating in unison and adopting specialized orientations exclusive of one another.
(A) beating in unison and adopting
(B) they beat in unison while adopting
(C) beat in unison, and adopt
(D) beating in unison yet adopting (E)even though they beat in unison and adopt 正确答案是D。哪位朋友能帮我翻译一下题干。O(∩_∩)O~题干没读明白，所以对于整个句子的逻辑结构也没弄清楚。作者: yahoochao 时间: 2010-4-5 21:01
自己顶一下~~~急盼NN出现！！！！！！！！作者: Eileenl 时间: 2010-4-5 22:02
哺乳动物的胚胎循环系统独有的特色是，在心脏的细胞彼此粘着，一起跳动，却独自adopting specialized orientations 。 不是NN，仅仅个人看法哈作者: yahoochao 时间: 2010-4-6 12:41