荆矿井田哪几个煤层为可采煤层,分别是()、()、()、()。
参考答案:9;11;12-1;12-2
I often doubt .
A.that this song is worth listening to
B.if this song is worth listening
C.that this song is worth listening
D.if this song is worth listening to
结核球的形成是干酪样坏死物被
A.机化B.钙化C.包裹D.排出