问题
单项选择题
The atmosphere in a tank is too lean if it is（）.
A.incapable of supporting combustion because the hydrocarbon content is below the LFL (Lower Flammable Limit)
B.capable of supporting combustion because the hydrocarbon content is above the UFL (Upper Flammable Limit)
C.capable of supporting a fire once started
D.not safe for ballasting
答案
参考答案：A