请教while的用法

我想请教一下1,while是不是表转折和表同时发生在主语相同情况下都可以用while+doing，区别在于标点，表转折是要用comma

2以下有几道题：

12.   (25105-!-item-!-188;#058&002139)

Performing a risky maneuver that required precision flying, not only did space shuttle astronauts retrieve an orbiting satellite, it was done simultaneously while avoiding being rear-ended by a passing ultraviolet telescope.

(A) not only did space shuttle astronauts retrieve an orbiting satellite, it was done simultaneously while avoiding

(B) not only was an orbiting satellite retrieved by space shuttle astronauts, but they also simultaneously avoided

(C) an orbiting satellite was retrieved by space shuttle astronauts who also avoided simultaneously
            

(D) space shuttle astronauts retrieved an orbiting satellite, simultaneously while avoiding

(E) space shuttle astronauts retrieved an orbiting satellite and simultaneously avoided

答案E

45.   (26816-!-item-!-188;#058&003335)

A recent poll indicates that many people in the United States hold a combination of conservative and liberal political views; i.e., they denounce big government, saying government is doing too much and has become too powerful, while at the same time supporting many specific government programs for health care, education, and the environment.

(A) they denounce big government, saying government is doing too much and has become too powerful, while at the same time supporting

(B) they denounce big government--they say that government is doing too much and has become too powerful--but supporting at the same time

(C) they denounce big government, they say that government is doing too much and it has become too powerful, while they support at the same time

(D) while they denounce big government, saying that government is doing too much and has become too powerful, at the same time supporting

(E) while they are denouncing big government--they say that government is doing too much and it has become too powerful-- supporting at the same time

答案是A

130.       (31416-!-item-!-188;#058&004490)

Industrialization and modern methods of insect control have improved the standard of living around the globe while at the same time they have introduced some 100,000 dangerous chemical pollutants, having gone virtually unregulated since they were developed more than 50 years ago.

(A) while at the same time they have introduced some 100,000 dangerous chemical pollutants, having

(B) while at the same time introducing some 100,000 dangerous chemical pollutants that have

(C) while they have introduced some 100,000 dangerous chemical pollutants at the same time, and have

(D) but introducing some 100,000 dangerous chemical pollutants at the same time that have

(E) but at the same time introduce some 100,000 dangerous chemical pollutants, having

第一道除了simultaneously位置不好，是不是还有while是表同时发生和simultaneously重复，问候两道题表转折所以at the same time不重复，还有就是最好while前面不用comma

谢谢！