We can learn from David Rakisons study that _____.
A. people develop fears for dangerous animals by learning
B. people are born with fears for dangerous animals
C. boys do not feel frightened by the pictures of spiders
D. girls are more attracted by beautiful flowers than boys do
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x^4-2x^2-3x+3在(2,4)内至少有1个根。()
参考答案:错误
财政分配的对象是()
A企业收入
B居民收入
C国民收入
D家庭收入