宏观煤岩成分可分为()、()、()、和()。
参考答案:镜煤;丝炭;亮煤;暗煤
In Grammar-Translation Method, ______ is maintained as the reference system in the learning of the second language.
A.the first language
B.the second language
C.the target language
D.the foreign language
鲜牛奶的鉴别方法有哪些?