食物中毒发生在学校的,应当于以下哪个时间内上报卫生部,并同时报告同级人民政府和上级人民政府卫生行政部门
A.2小时
B.4小时
C.6小时
D.8小时
E.12小时
参考答案:C
已知xm=5,xn=3,则x3m-2n=______.
Before going abroad, she spent as much time as she could_____her spoken English. [ ]
A. practise
B. to practising
C. practising
D. to practise