根据《突发公共卫生事件应急条例》第十五条规定,监测与预警工作应当根据突发事件的(),制定监测计划,科学分析、综合评价监测数据。
A.类别
B.程度
C.等级
D.时间
参考答案:A
Someone is knocking at the door. It ____ my mother. It's time for her to be back. [ ]
A. can be
B. may not be
C. must be
D. mustn't be
容受性舒张