VOA慢速英语:巴黎圣母院火灾产生的有毒铅尘

threshold – n. the point or level at which something begins or changes

uNPRecedented – adj. not done or experienced before

seizure –n. medical : an abnormal state in which you become unconscious and your body moves in an uncontrolled and violent way

coma –n. a state in which a sick or injured person is unconscious for a long time

preserved – adj. kept in good condition over a long period of time

incineration – n. the complete burning of something

alchemy – n. a science that was used in the Middle Ages with the goal of changing ordinary metals into gold : a power or process that changes or transforms something in a mysterious or impressive way

precious – adj. very valuable or important : too valuable or important to be wasted or used carelessly