请教几道语法题

以下是引用st_ale在2006-4-13 23:20:00的发言：
都是新东方上课发的黄皮语法教程上的。
Exercise 22
23.Graviation keeps the Moon in orbit around Earth and  the other planets of the solar system in orbit around the
Sun.
Earth 前不用加The么？Sun和Moon前不都加了么？！'around earth' is a fixed phrase.  no "the", well, "on earth" is a fixed phrase, too.

Exercise 25
27.Someone may refuse to reognize the seriousness of an emotionally threatening situation and perceives as less
threatening.
这句话啥意思啊？
perceive改成什么呢？ someone may refuse ......and perceives....

Exercise 26
13.In western North America,_________ from the Great Divide,which separates the areas from which waters flow either eastward to the Atlantic or westward to the Pacific.
A)the Rocky Mountains
为什么要选它阿？是一个什么用法。"the Rocky Mountains" is in western North America.

36.The pulse that may be felt wherever an artery passes over a solid structure,such as a bone or cartilage.
                     _______
                          A
A怎么错了？应该改成什么？没胃语呀, 去掉 that.  the pulse may be felt wherever .........

38。The "method",which is both a style of acting and a system of training for the actor,stresses inner motivation and
                                                                    _____
                                                                       B
psychological truth.
B怎么错了？改成什么。  both ... and ...

谢谢各位了！~