第31题: [单项选择]How is the quartz heater different from other types of heaters
a. It heats only the objects in a room.
b. It is lighter in weight.
c. It heats the room quicker.
d. It is more common. 参考答案:A 答案解析:[听力原文]
A heater is using convection when it warms the air in a room. And the air in turn warms the
第32题: [单项选择]下列哪项受损伤对肛管括约功能影响最大() A. 肛提肌 B. 内括约肌 C. 外括约肌的深部 D. 外括约肌的皮下部 E. 肛管直肠环 参考答案:E