生产石灰用致密石灰石的色彩由于所含杂质的不同而不同,当其含()时呈浅灰或深灰色。
A、镁、锰
B、黄铁矿
C、石英
D、碳化物及沥青质
参考答案:D
-_______
-The long jump.[ ]
A.What sport will you take part in?
B.Which sport will you take part in?
C.What are you going to do?
D.What's the matter?
肉品辐射保存的优点有哪些?