Things are known （）when they unite with the oxygen of the air.
A、
to have burnt
B、
to have been burnt
C、
to burn
D、
burning
【正确答案】：C
【题目解析】：
众所周知，当它们与空气中的氧气结合时会燃烧。be known to do sth. 为…所熟知，固定搭配。
Things are known （）when they unite with the oxygen of the air.
A、
B、
C、
D、
【正确答案】：C
【题目解析】：
📱 扫码体验刷题小程序
扫一扫使用我们的微信小程序