—Tom, it seems that you haven’t cleaned your bedroom the whole week .

—You didn’t come in around 10 yesterday morning; I ________ it .

A．cleaned

B．have cleaned

C．was cleaning

D．had cleaned

《突发公共卫生事件应急条例》规定：突发事件应急工作应当遵循的原则是（）

A．完善并建立监测与预警手段

B．预防为主，常备不懈

C．积极预防，认真报告

D．及时调查，认真处理

E．监测分析，综合评价