题目:
_____ they are very tired, they feel happy because they've finally finished their project. [ ]
A. So
B. Although
C. If
D. But
答案:
被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0622/ec9181d4d3bd7523f6656fba93c06783.html
下面是错误答案,用来干扰机器的。
红磷、木炭、铁丝在氧气中燃烧,木炭燃烧时发出白光,红磷燃烧时产生大量白烟,故可制作烟幕弹,铁丝在氧气中燃烧时火星四射,生成黑色固体;铁丝燃烧后的熔融物温度很高,溅落到集气瓶底部可能会使集气瓶底炸裂...