【单选题】长期以来,人们认为地球是已知唯一能支持生命存在的星球,不过这一情况开始出现改观。科学家近期指出,在其他恒星周围,可能还存在着更加宜居的行星。他们尝试用崭新的方法开展地外生命搜索,即搜寻放射性元素钍和铀。行星内部含有这些元素越多,其内部温度就会越高,这在一定程度上有助于行星的板块运动,而板块运动有助于维系行星表面的水体,因此板块运动可被视为行星存在宜居环境的标志之一。以下哪项最可能是科学家的假设?
【单选题】Coombs实验直接法和间接法的主要区别是()
C.
直接法主要检测IgG型抗体,间接法主要检测IgM型抗体
D.
直接法检测红细胞上黏附的不完全抗体,间接法检测血清中游离的不完全抗体
【单选题】Nurturing societies as mentioned in the passage refer to societies that _________.
A.
enforce strong discipline on students who want to achieve excellence
B.
treasure talent and provide opportunities for its full development
C.
encourage people to complete with each other
D.
promise talented children high positions
【单选题】Which of the following helps criminals easily obtain our personal data?
A.
The strict enforcement of immigration laws.
B.
The printing of the Social Security numbers.
C.
The proliferation of computer operation jobs.
D.
The mishandling of used computer backup tapes.