(2013·甘肃兰州名校高三检测)Many people believe that hunger is only a problem in the developing countries.________， it is a problem all over the world.

A．For one thing

B．In addition

C．As well

D．On the contrary

利用高压蒸汽灭菌，灭菌时间要从……计时（）

A、关闭灭菌柜时

B、打开进气阀后3分钟

C、预热5分钟夹层压力表达到灭菌的压力时

D、灭菌器的柜室内达到要求温度后

E、预热10分钟，冷空气由柜室阻气器排出时