n.

any of various water-soluble compounds capable of turning litmus blue and reacting with an acid to form a salt and water

同義詞：base

a mixture of soluble salts found in arid soils and some bodies of water; detrimental to agriculture

1. Alkalis, such as sodium hydroxide, are commonly used in industrial cleaning.
   堿性物質(zhì)，如氫氧化鈉，常用于工業(yè)清潔。
2. The soil needs to be treated with alkalis to neutralize its acidity.
   土壤需要用堿性物質(zhì)處理，以中和其酸性。
3. Alkalis react with acids to form salts and water.
   堿性物質(zhì)與酸反應(yīng)生成鹽和水。
4. The laboratory technician carefully handled the alkalis to avoid accidents.
   實(shí)驗(yàn)室技術(shù)員小心地處理這些堿性物質(zhì)，以避免事故發(fā)生。