[单项选择]下列关于施工现场灭火器配置说法正确的是（）。
A. 办公用房、宿舍的单具灭火器最小灭火级别为1A
B. 有固体物质火灾危险的临时动火作业点的单具灭火器最小灭火级别为1A
C. 有固体物质火灾危险的厨房操作间的单具灭火器最小灭火级别为1A
D. 有固体物质火灾危险的固定动火作业场的单具灭火器最小灭火级别为2A

In the 1980s, scientists around the world began to notice something strange: Frogs were disappearing. More recent research has shown that many kinds of amphibians (两栖动物) are declining or have become extinct. They have been around for a long time—over 350 million years. Why are they dying out now
Scientists are seriously concerned about this question. First of all, amphibians are an important source of scientific and medical knowledge. By studying amphibians, scientists have learned about new substances that could be very useful for treating human diseases. Further research could lead to many more discoveries, but that will be impossible if the amphibians disappear.
The most serious aspect of amphibian loss, however, goes beyond the amphibians themselves. Scientists are beginning to think about what amphibian decline means for the planet as a whole. If the
A. in any stream they can find
B. in places without UV light
C. only on sand
D. only in the right conditions