牙周炎患者牙齿松动最主要的原因是
A．牙周炎引起的牙槽嵴的吸收
B．创伤
C．牙周韧带的急性炎症
D．牙周翻瓣手术后
E．女性激素水平的变化
参考答案：A
下列加点的字的注音全都正确的一项是
A．慰藉jí栈道zhàn庖厨páo忐忑tán tè
B．吮血shǔn 酒馔zhuàn口讷nà挟持xié
C．戏谑xuè青冢zhǒng商贾gǔ伉俪kàng
D．省亲xǐng 猿猱náo赧然nǎn菜畦jì
These toys are not suitable for children _____ four years old, who are too young. [ ]
A. outside
B. beyond
C. under
D. within
