________ the teachers is about 300 in our school and it is becoming_____________.

A．The number of, more and more

B．The number of, bigger and bigger

C．A number of, more and more

D．A number of, bigger and bigger

在开展疾病的一级预防时，经常采用的双向策略是指

A．临床医护人员参与的预防和高危人群自我预防的结合
B．预防专家参与的预防和整个人群参与的结合
C．临床医护人员参与的预防和防疫专家参与的预防的结合
D．整个人群的普遍预防和高危人群的重点预防
E．以上都不是