Mary: What do you think of my new dress?

Sue: ________.

A．It is on sale

B．You really have a new dress

C．It looks very good on you

D．I think it’s a birthday present for you

如图所示，取三根粗细、长度均相同的光亮细铁丝，将其中两根分别盘成螺旋状，在每根铁丝一端绑上粗铜丝，另一端系一火柴，点燃火柴，带快燃尽时，分布插入充满氧气的集气瓶中（预先放入一些水）．观察到：Ⅰ、Ⅱ中铁丝都剧烈燃烧，且Ⅱ中铁丝比Ⅰ中的更剧烈；Ⅲ中铁丝没有燃烧．

（1）Ⅲ中铁丝不能燃烧的原因是______．

（2）Ⅱ中铁丝燃烧比Ⅰ中的更强烈的原因是______．