菱铁矿的主要成分是FeCO3。下列有关说法正确的是（） A．菱铁矿

菱铁矿的主要成分是FeCO₃。下列有关说法正确的是（）

A．菱铁矿是铁的合金 B．FeCO₃是含有氧元素的化合物

C．FeCO₃中铁的化合价为+3 D．菱铁矿中铁元素的质量分数为48.3%

答案

相关题目

She is going to collect________ tonight. A. as many interesting story as she ca

She is going to collect________ tonight. A. as many interesting story as she can B. as much interesting story as she can C. as much interesting stories as she can D. as many intere

用显微镜观察洋葱鳞片叶表皮细胞的临时装片的同一部位时

用显微镜观察洋葱鳞片叶表皮细胞的临时装片的同一部位时，若要在视野中所看到的细胞数目最少，在如下的目镜和物镜组合中，应选择（）A．目

若平面α∥平面β，直线aα,点B∈β，则在β内过点B的所有直线

若平面α∥平面β，直线aα,点B∈β，则在β内过点B的所有直线中( )A.不一定存在与a平行的直线 B.只有两条与a平行的直线C.存

---If you to my birthday party last Saturday, you would have met J

---If you to my birthday party last Saturday, you would have met Jim. ---I was not in Beijing then, otherwise I to your party. A．came; would have come B

–Jimmy had a lot of parties recently. —Yes, that might why he d

–Jimmy had a lot of parties recently. —Yes, that might why he didn’t do well in the test. A．sum up B．add up to C．account for D．make sense of

—What do you think of the cake? —Very delicious and quite different from I

—What do you think of the cake? —Very delicious and quite different from I had last week. A. that B. the one C. what D. which

仿照下面的例子，在①②处各写一句话，要求与前句内容一

仿照下面的例子，在①②处各写一句话，要求与前句内容一致，句式相仿，在③处写一句结论性的话。（3分) 我渴望智慧，上帝却给我问题，让我解决

北京2008年奥运会有一个口号“One World，One Dream”。下列事件

北京2008年奥运会有一个口号“One World，One Dream”。下列事件中将相互隔绝和孤立发展的各个地区连成“One World”——“同一个世界”的历史事件是 A．

菱铁矿的主要成分是FeCO3。下列有关说法正确的是（ ） A．菱铁矿

答案

相关题目

最新题目

菱铁矿的主要成分是FeCO3。下列有关说法正确的是（） A．菱铁矿