以下不是地表次生且松散状的矿物的是: A.
钴华 B.
辰砂 C.
钨华 D.
锡华

多项选择题The major differences between public speaking and conversation include: A、Public speaking is more intentional than conversation. B、Public speaking is less interactive than conversations. C、Public speaking is more formal than conversations. D、Public speaking is more interactive than conversations.

多项选择题京杭大运河沟通( )等河流,是世界上最长的一条人工运河。 A. 海河 B. 黄河 C. 淮河 D. 长江 E. 珠江