Boys are often kept close to their parents while girls are encouraged to move on their own.
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Some people believe that gender differences may change if boys and girls are encouraged to learn and solve problems in the same way.
A. 对
B. 错
直通式空气制动机比自动式空气制动机少一个三通阀
A. 对
B. 错
视网膜的输出可以完全忠实地反映出当前的光强度。()
A. 对
B. 错
属于空性的器官是：
A. 肝
B. 脾
C. 肾
D. 胃
E. 胰
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