元素的存在形式：
参考答案：
A、独立矿物
B、类质同象
C、固溶体分离
D、包裹物E、吸附
F、天然溶液中存在。
地下资源量
I am very surprised that even an expert on foreign affairs can know the painting is forgery. （）he can tell who painted it.
A.However
B.Otherwise
C.Nevertheless
D.Moreover
