The best title for the text may be
A．We Can Live Longer in the 21st Century.
B．Cancer Can Be Conquered Soon.
C．The Final Frontier of the 21st Century.
D．Scientific Breakthroughs of the 21st Century.

未分类题实质性测试有()基本类型。

判断题在排水较困难的挖方和填方路段，只须采用相应的隔离层措施即可解决问题。()

未分类题The author and his colleagues cognitive tests proved thatA．the children were more skillful in all aspects.B．the children were not the same as the apes in dealing with the material world.C．the children performed better only in social skills.D．the apes were better in the physical world.

判断题我国公路自然区划的一级区划是按自然气候、全国轮廓性、地理、地貌、各地方的年降雨量划分的。()

未分类题It can be inferred that cracking the genetic code and conquering cancer are related becauseA．the latter can be achieved based on the knowledge of the former.B．the latter can prove the existence of the former.C．the former reverses the process of the latter.D．the former generates the therapeutic viruses for the latter.

未分类题According to the passage, the aging process is a struggle betweenA．destruction and repair.B．damage and control.C．control and reverse.D．repair and reverse.

判断题护面墙除承受自重外，不能承受墙背土压力。()

未分类题The author uses the result of Gallup poll to argue thatA．the first ladies in America are respected by the whole nation.B．Rosalynn is not as good as Nancy Reagan in the 1980s.C．Gallup poll is an effective organization to collect public opinions.D．today's famous people are created for their well-knowness.

判断题励磁绕组断线的他励直流电动机，额定负载起动时，将出现电流过大情况。()

未分类题The phrase 'putting their heads together'(Lines 7-8, Paragraph 3)meansA．making efforts collectively.B．always getting together.C．thinking in the same way.D．chatting together.

判断题三相异步电动机根据转子结构的不同，分为笼型异步电动机和绕线型异步电动机。()

未分类题According to Brand, older workers suffered less than young laid-off workers becauseA．young workers feel more humiliated at being laid off than older people.B．older workers want to retire earlier to enjoy their life.C．young workers cannot get used to the life after being laid off.D．older workers do not worry about their retirement life after being laid off.

判断题同一台异步电动机，用三角形接法起动和用星型接法起动相比，前者的起动电流(线电流)是后者的3倍;前者的起动转矩是后者的3倍。()

判断题一台380V、50Hz的感应电动机，把它接在380V、60Hz的电源上运行，则电机的主磁通将下降;电机的最大转矩将下降。()

未分类题Why does the system fail to arrest a wanted person?A．The system is not effective in recognizing people.B．The system does not look at skin color or one's gender.C．The system does not consider people's specific features.D．The system is highly inaccurate and can be easily fooled.