主权国家的构成要素包括（）
①人口
②领土
③ * *
④主权
A.①②③④
B.①②③
C.①③④
D.②④
参考答案：A
读一读，选出正确单词填空。
1. Middy is (yonger, younger) than his brother.
2. Middy is (older, oulder) than her sister.
3. Middy is (shoter, shorter) than Mike.
4. Middy is (taller, toller) than Mary.
假性牙周袋又称为
A．龈袋 B．骨上袋 C．骨下袋 D．复合袋 E．复杂袋
