烧还原焰的作用是什么？
参考答案：
A、使坯体中的氧化铁还原成氧化亚我铁；使硫酸盐在较低温度下分解。
---European scientists announced that the speed of light isn’t the speed limit.
---Perhaps it is the biggest challenge to Einstein’s Theory of Relativity. No one _____ any crack in his
theory for more than a century. [ ]
A. has found
B. found
C. had found
D. would find
下列关于阿司匹林的叙述，正确的是（）。
A.只降低过高体温，不影响正常体温
B.采用大剂量可预防血栓形成
C.抗炎作用弱
D.几乎无抗炎作用
E.以上都不是
