Hardness ions
[化] (水的)硬度离子(指水中的钙、镁等离子)
🧩 词语组成解析
hardness
['hɑrdnɪs]
n. 坚硬;<物>硬性;困难;冷酷;
n. 离子（ion复数）
🗣️ 情景例句
Before a long trip I always give my car a safety check.
远行之前，我总是会对车子进行安全检查。
Which one do you prefer?
你比较喜欢哪一个？
After they had entered the house, they went into the dining room.
他们进到屋里后，走进了饭厅。