单选题 .  During recent years we have heard much about "race": how this race does certain things and that race believes certain things and so on. Yet, the,     1    phenomenon of race consists of a few surface indications.
    We judge race usually     2    the colouring of the skin: a white race, a brown race, a yellow race and a black race. But     3    you were to remove the skin you could not     4    anything about the race to which the individual belonged. There is     5    physical structure, the brain or the internal organs to     6    a difference.
    There are four types of blood.     7    types are found in every race, and no type is distinct to an race. Human brains are the     8    . No scientists could examine a brain and tell you the race to which the individual belonged. Brains will     9    in size, but this occurs within every race.     10    does size have anything to do with intelligence. The largest brain     11    examined belonged to a person of weak     12    . On the other hand, some of our most distinguished people have had     13    brains.
    Mental tests which are reasonably     14    show no differences in intelligence between races. High and low test results both can be recorded by different members of any race.     15    equal educational advantages, there will be no difference in average standings, either on account of race or geographical location.
    Individuals of every race     16    civilization to go backward or forward. Training and education can change the response of a group of people,     17    enable them to behave in a     18    way.
    The behavior and ideals of people change according to circumstances, but they can always go back or go on to something new     19    is better and higher than anything     20    the past.1.