岩浆侵入对煤矿生产将产生什么样的影响?
参考答案:
减少煤炭储量、缩短矿井服务年限;使煤质变差,灰分增高、挥发分降低,粘结性破坏;破坏煤层连续性。
With ________ word “PM 2.5” repeatedly appearing in ________ media reports, the public can’t help wondering what it really means.
A.the; \
B.a; the
C.the; the
D.\; the
A.5A
B.5A
C.5/2A
D./2A