[单选题]烧伤急救时，强酸或碱灼伤应迅速脱去被溅染衣物，现场立即用大量清水彻底冲洗，要彻底，然后用适当的药物给予中和；冲洗时间不少于( )min。
A.5
B.10
C.15
D.20

Although we already know a great deal about influenza, and although the World Health Organization is constantly collecting detailed information from its chain of influenza reference laboratories throughout the world, it is extremely difficult for epidemiologists, who study infectious disease, to predict when and where the next flu epidemic will occur, and how severe it will be.
There are three kinds of influenza virus, known as A, B and C. Influenza C virus is relatively stable and causes mild infections that do not spread far through the population. The A and B types are unstable, and are responsible for the epidemics that cause frequent concern. Following any virus attack, the human body builds up antibodies which confer immunity to that strain of virus, but a virus with the capacity to change its character is able to by-pass this protection. Variability is less developed in the influenza B virus, which affects only human b
A. Man has obtained a great deal of knowledge about influenza.
B. The occurrence of influenza is still unpredictable.
C. Extensive and systematic study on influenza is being done.
D. No reliable treatment of influenza has yet been found.