Because they react dangerously with fire. Thus, they are flammable.
water. i don't know what else but I'll get back to you
Flammability is defined at how easily something will burn or ignite, causing fire or combustion. The degree of difficulty required to cause the combustion of a substance is subject to quantification...
the school.
Almost all substances I can't think of any that aren't but there probably are that aren't flammable! xxx