EX1:
More than 300 rivers drain into Siberia's Lake Baikal, which holds 20 percent of the world's fresh water, more than all the North American Great Lakes combined.
(A) More than 300 rivers drain into Siberia's Lake Baikal, which holds 20 percent of the world's fresh water, more than all the North American Great Lakes combined.
(B) With 20 percent of the world's fresh water, that is more than all the North American Great Lakes combined, Siberia's Lake Baikal has more than 300 rivers that drain into it.
(C) Siberia's Lake Baikal, with more than 300 rivers draining into it, it holds more of the world's fresh water than all that of the North American Great Lakes combined, 20 percent.
(D) While more than 300 rivers drain into it, Siberia's Lake Baikal holds 20 percent of the world's fresh water, which is more than all the North American Great Lakes combined.
(E) More than all the North American Great Lakes combined, Siberia's Lake Baikal, with more than 300 rivers draining into it, holds 20 percent of the world's fresh water.
OA:A. 可是A的谓语在哪呢？
EX2:
Whereas in mammals the tiny tubes that convey nutrients to bone cells are arrayed in parallel lines, in birds the tubes form a random pattern.
A. Whereas in mammals the tiny tubes that convey nutrients to bone cells are arrayed in parallel lines, in birds the tubes
B. Whereas the tiny tubes for the conveying of nutrients to bone cells are arrayed in mammals in parallel lines, birds have tubes that
C. Unlike mammals, where the tiny tubes for conveying nutrients to bone cells are arrayed in parallel lines, birds’ tubes
D. Unlike mammals, in whom the tiny tubes that convey nutrients to bone cells are arrayed in parallel lines, the tubes in birds
E. Unlike the tiny tubes that convey nutrients to bone cells, which in mammals are arrayed in parallel lines, in birds the tubes
OA：A。
A选项中的逗号后面in birds the tubes form a random pattern.的谓语呢？
费解啊~ 大家帮帮我~