The Oxford 5000 words
The Oxford 5000 is an expanded core word list for advanced learners of English. As well as the Oxford 3000 core word list, it includes an additional 2,000 words that are aligned to the CEFR, guiding advanced learners at B2-C1 level on the most useful high-level words to learn to expand their vocabulary.
that contains acid or has the essential characteristics of an acid; that has a pH of less than seven
a chemical, usually a liquid, that contains hydrogen and has a pH of less than seven. The hydrogen can be replaced by a metal to form a salt. Acids usually have a bitter sharp taste and can often burn holes in or damage things they touch.
一種化學物質，通常為液體，含有氫且 pH 值小於七。其中的氫可被金屬取代而形成鹽。酸通常帶有苦澀刺激的味道，且常會在所接觸的物體上燒出洞或造成損壞。
used to emphasize an adjective or adverb in negative sentences or questions, meaning ‘at all’
used with uncountable or plural nouns in negative sentences and questions, after if or whether, and after some verbs such as prevent, ban, forbid, etc. to refer to an amount or a number of something, however large or small
與不可數名詞或複數名詞連用，用於否定句與疑問句、if 或 whether 之後，以及 prevent、ban、forbid 等動詞之後，指某物的數量或數目，無論多寡
calculated by adding several amounts together, finding a total, and dividing the total by the number of amounts