litmus
🇺🇸
/ˈlɪtməs/
🇬🇧
/ˈlɪtməs/
a special paper that changes color to red in sour liquids and blue in soapy liquids.
In science class, we used a piece of litmus paper to see if the liquid was acid or base.
在科学课上,我们使用一张立特纸来检测液体是酸性还是碱性。