灰质是指脑和脊髓中_______的部位。 [ ]
A．神经元集中
B．神经元及其树突密集
C．神经元及神经节密集
D．神经元的细胞体密集
答案：D
根据图片把短文补充完整，每空一词。
My friend is Tom He is1.______ years old. He goes to school 2._______．He gets
up3.______ every day. He has4.______ and 5.______ at school. In spring, he
6._______. In summer, he swims. In autumn, he 7._______. In winter, he
8.________．He likes 9._______ and 10._______.He doesn't like11.______.
（）保证了期货和现货价格趋向一致。
A．保证金制度
B．交割制度
C．风险准备金制度
D．限额持仓制度
1.______ years old. He goes to school 
2._______．He gets 
3.______ every day. He has
4.______ and 
5.______ at school. In spring, he 
6._______. In summer, he swims. In autumn, he 
7._______. In winter, he 
9._______ and 
10._______.He doesn't like
11.______.