单项选择题
某校六年级(12岁年龄组)300名学生中恒牙有龋、失、补的人数为180人，未治龋齿数为328个，因龋失牙数为3个，因龋充填牙数为69个。
该年级学生的患龋率为（）。
A．64% B．62% C．60% D．58% E．56%
单项选择题 The sentence "take the lightest possible approach in confirming identity" (Paragraph 7) means that ______.
单项选择题 Which of the following is NOT true about loyalty cards
单项选择题 When escaping from their homes, many people ______.
