1.After the national speed limit of 55 miles per hour was imposed in 1974, the number of deaths per mile driven on a highway fell abruptly as a result. Since then, however, the average speed of vehicles on highways has risen, but the number of deaths per mile driven on a highway has continued to fall.
Which of the following conclusions can be properly drawn from the statements above?
(A) The speed limit alone is probably not responsible for the continued reduction in highway deaths in the years after 1974.
(B) People have been driving less since 1974.
(C) Driver-education courses have been more effective since 1974 in teaching drivers to drive safely.
(D) In recent years highway patrols have been less effective in catching drivers who speed.（A）
(E) The change in the speed limit cannot be responsible for the abrupt decline in highway deaths in 1974.
我想不通E为什么不行
2.Lark Manufacturing Company initiated a voluntary Quality Circles program for machine operators. Independent surveys of employee attitudes indicated that the machine operators participating in the program were less satisfied with their work situations after two years of the program’s existence than they were at the program’s start. Obviously, any workers who participate in a Quality Circles program will, as a result, become less satisfied with their jobs.
Each of the following, if true, would weaken the conclusion drawn above EXCEPT:
(A) The second survey occurred during a period of recession when rumors of cutbacks and layoffs at Lark Manufacturing were plentiful.
(B) The surveys also showed that those Lark machine operators who neither participated in Quality Circles nor knew anyone who did so reported the same degree of lessened satisfaction with their work situations as did the Lark machine operators who participated in Quality Circles.
(C) While participating in Quality Circles at Lark Manufacturing, machine operators exhibited two of the primary indicators of improved job satisfaction: increased productivity and decreased absenteeism.
(D) Several workers at Lark Manufacturing who had participated in Quality Circles while employed at other companies reported that, while participating in Quality Circles in their previous companies, their work satisfaction had increased.（E）
(E) The machine operators who participated in Quality Circles reported that, when the program started, they felt that participation might improve their work situations.
请问C 为什么不对?
3
Child’s World, a chain of toy stores, has relied on a “supermarket concept” of computerized inventory control and customer self-service to eliminate the category of sales clerks from its force of employees. It now plans to employ the same concept in selling children’s clothes.
The plan of Child’s World assumes that
(A) supermarkets will not also be selling children’s clothes in the same manner
(B) personal service by sales personnel is not required for selling children’s clothes successfully
(C) the same kind of computers will be used in inventory control for both clothes and toys at Child’s World
(D) a self-service plan cannot be employed without computerized inventory control（B）
(E) sales clerks are the only employees of Child’s World who could be assigned tasks related to inventory control
请问C为何不行? | 
