突出的类型有：
①煤与瓦斯喷出
②煤与瓦斯压出
③煤与瓦斯（）
A.喷出
B.涌出
C.倾出
参考答案：C
Which of the following signs shows “For the disabled to go through”?
Technological changes are most likely to result in which of the following effects Evolving technology is likely to result in changes in:
A. educational curriculum only.B. educational curriculum and the relative demand for various products.C. the relative demand for various products only.
