离心泵进行油品作业时应()
A.先打开出口伐
B.启泵前关出口伐
C.关闭罐根伐
参考答案:B
Peter survived in the accident when he fell overboard yesterday. He _______escaped drowning.
A.nearly
B.slightly
C.hardly
D.narrowly
喷雾消毒法中不正确的是()。
A、喷雾前必须将室内的食品转移
B、根据物品特性选择合适消毒剂
C、严格掌握消毒剂的有效浓度、消毒时间和方法
D、在有人情况下,喷洒前应将门窗关闭,到规定时间后再开窗通风