Impurities
n. 杂质（impurity的复数）
🗣️ 情景例句
any just cause why these two people
任何正当理由说明这两位
What are you thinking about?
你正在考虑什么？
But instruments far more delicate than that were needed if any really serious advance was to be made.
但是，如果要取得真正重大的进展，需要有比这种装置精细得多的仪器。