He is student at Oxford University, _____ for a degree in computer seience. [ ]

A. studied

B. studying

C. to have studied

D. to be studying

根据对蜡烛及其燃烧的探究，请完成下列内容：

（1）在蜡烛点燃前，蜡烛呈______形状，______色固体，用小刀可切割，说明蜡烛质地较______，切一小块放入水中，______溶于水，并能______在水面上，说明蜡烛密度比水______．

（2）蜡烛能被点燃，且有火焰产生，火焰分为三层，______层最明亮，______层最暗，______层温度最高，原因是______．

（3）熄灭后，______从灯芯飘出，用火迅速点燃，火能否会顺着该物质将蜡烛点燃？______．