Not only______ interested in football but _____ beginning to show an interest in it. [ ]

A. the teacher himself is; all his students are

B. the teacher himself is; are all his students

C. is the teacher himself; are all his students

D. is the teacher himself; all his students are

小科发现取自实验室的镁带表面有黑色物质，黑色物质是什么？会不会是镁带缓慢氧化后产生的氧化镁？

（1）小科把磨去黑色物质的镁带放在______（填化学式）中燃烧，结果得到的是白色固体．由此，他得出结论：黑色物质不是氧化镁．

（2）进一步查阅资料后获知，任何固体颗粒直径小到一定量时，颜色都是黑色的．如纯净的铁块是银白色的，而铁粉是黑色的．由此，小科认为原来的结论______．

A．正确      B．不正确       C．可能不正确

（3）小科又开始了进一步的探究…

此探究过程给你的启示是______．