All substances, ＿＿＿＿＿ solids, liquids, or gases, are made up of entirely atoms.

A．whether they

B．whether

C．whether are they

D．whether are

下列变化过程一定发生化学反应的是（　　）

A．燃烧

B．爆炸

C．颜色发生了改变

D．状态发生了改变