研究某口腔医院过去几年来初诊主诉变化的流行病学方法，称为
A．横断面研究
B．纵向研究
C．常规资料分析
D．病例对照研究
E．群组研究
参考答案：C
单项选择。
— do you go to school every day?
— At seven in the morning. [ ]
A. When
B. Which time
C. How
D. How much
The underlined part in the word “create” is probably pronounced as .
A．[i]
B．[i:]
C．[ei]
D．[æ]
