, coal from this era was mostly smoky coal, so windows had to be opened for ventilation. Otherwise, within a quarter of an hour, the smoke would make people's eyes water incessantly.Li Chen remembered... don't need you to wait on me. Make sure you are well prepared, it's always good."Su Pingbei let out an "en" and was about to turn away when, as if remembering something, he turned back and said, "You...