And, apparently, that day has come because seemingly routine operations such as knee replacements are now much more hazardous due to the looming threat of these infections.
2017年6月六级真题（第一套）听力 Section B
柯林斯高阶英汉双解学习词典释义
N-UNCOUNT
替代;替换;取代
If you refer to the replacement of one thing by another, you mean that the second thing takes the place of the first.