请教两道PREP1的题，谢谢

33.   (26233-!-item-!-188;#058&002541)

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)

(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.

 A好像没有谓语动词啊

39.   (26509-!-item-!-188;#058&002648)

The Sports Medicine Programs of the Olympic Training Center, a complex where final tryouts are held for athletes representing the United States in the Olympics, is geared toward enhancing athletes' performance and toward their preparation for international competition.(E)

(A) is geared toward enhancing athletes' performance and toward their preparation

(B) is geared to enhance the performance of athletes and to prepare them

(C) are geared to enhance athletes' performance and their preparation

(D) are geared toward the enhancement of athletes' performance and toward preparing them

(E) are geared toward enhancing the performance of athletes and preparing them

39.   (26509-!-item-!-188;#058&002648)

The Sports Medicine Programs of the Olympic Training Center, a complex where final tryouts are held for athletes representing the United States in the Olympics, is geared toward enhancing athletes' performance and toward their preparation for international competition.(E)

(A) is geared toward enhancing athletes' performance and toward their preparation

(B) is geared to enhance the performance of athletes and to prepare them

(C) are geared to enhance athletes' performance and their preparation

(D) are geared toward the enhancement of athletes' performance and toward preparing them

(E) are geared toward enhancing the performance of athletes and preparing them

toward ing + ing

我的问题是， The Sports Medicine Programs of the Olympic Training Center, a complex  --》推出应是单数。

看来complex应该是修饰center的，这样的话，我觉得主语也太遥远了

前面一题，我已经回答了，

后面一题，我选E的理由是

两个考点

PROGRAMS是复数，肯定是ARE

所以排除A和B

第二个考点是平行TOWRAD，其中永远记住除非是介词短语那么后面用实意名词比较好，类似于这种PREPARATION，不觉得太抽象了，GMAC绝对不用这种表达方式的，绝对用PREPARING和前面的ENHANCING并列平行。故此选E

33 D 为什么不对啊

A 最后一部分是什么成分呢？

盼解答

33题最后一部份是作同位语修饰20 percent of the world's fresh water

我对(D)有同样的疑惑

which不能指代名词短语吗？ 只有同位语可以？