演示铁在纯氧中燃烧实验时,将铁丝绕成螺旋状,其主要目的是( )
A:提高铁丝利用率
B:使瓶底氧气充分利用
C:提高反应的温度
D:增大反应的接触面积
—I don't care what people think.
—Well, you ___. You're not alone in this world.
—The problem is too difficult,can you show me _____,Wang Le? —Sure.