放在水平地面上的小车，用力推它就运动，不推它就不动。下列说法中不正确的是[ ]

There is a growing number of economists who believe today’s brutally tough labor market is not a temporary American oddity. Falling wages, reduced benefits and rising job insecurity seem to be increasingly entrenched features of the job scene across most of Western Europe, the United States and other parts of the developed world. The number of insecure freelance positions is rising (as are working hours) while stable jobs with good benefits are being cut. Laid-off workers are much less likely to be rehired by their old companies and have to find new jobs or turn to self-employment. Those who still have jobs are working longer hours with little prospect of meaningful raises. The new labor market is shaped by growing global competition, spurred by the rise of cheap manufacturers in China, India and Eastern Europe, and the price-chopping effect of both the Internet and giant retailers led by Wal-Mart. These forces compel Western companies to exercise a growing restraint on prices and labor cost. One thing globalization clearly does is to exert a leveling effect on wages.

风险是衡量危险性的指标，是某一有害事故发生的（）与事故后果的组合。

A.影响性

B.可能性

C.不可预见性

D.可预见性

设a＜0，b＜0，且a²+b²=7ab，那么=（）。

A.A

B.B

C.C

D.D

E.E

老年人长期服药酒好。

室内质量控制（）

A.可用来监测方法或检测系统的准确性

B.可评价检测结果的精密度

C.可用于比较某一实验室的测定结果与靶值的差异

D.可以使实验室间的结果具有可比性

E.可以提高实验室常规工作批内／批间检验结果的一致性