The decision was made ________ more medical teams would be sent to help people in  the earthquake.

A．what

B．which

C．that

D．when

下列属于主动监测的是（）

A.法定传染病报告系统

B.卫生防疫部门开展的传染病漏报调查

C.行为危险因素监测

D.以医院为基础的监测系统

E.单病种如流行性感冒、艾滋病、出血热、伤寒等的监测