句法成分？

Spencer125

21. 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
答案是D
我想问一下 in the area of the heart the cells adhere to one another, beating in unison yet adopting specialized orientations exclusive of one another.
这句话的句法成分怎么分析？   in the area of the heart the cells adhere to one another, 谁是主语，那个是谓语？  如果cells是主语，那么为何前面还要有in the area of.???

Spencer125

uppppppppppppppppppppp

PMFTOTC

cells是主语
in the area of the heart 是 prep
有什么问题？

Spencer125

PMFTOTC 发表于 2013-10-15 16:18
cells是主语
in the area of the heart 是 prep
有什么问题？

介词和主语之间没有逗号吗？