1. 不可数名词：加；加法
2. 可数名词：增加物；添加物
3. 不可数名词：增加；添加 词形变化
- 形容词 additional
- 副词 additionally
- 这些名词均含“附加物、增加物”之意。
addition仅强调数量的增加。
appendix指书末的附录。
attachment指用于扩大原物用途的附件。
supplement主要指使书、报等正广更完善而额外增加的部分。
accessory作“附件”解时，与attachment同义，可互换，但还指增加美观的附属品。
- a suburban area laid out in streets and lots for a future residential area
- something added to what you already have
- a quantity that is added
- the act of adding one thing to another
- a component that is added to something to improve it
- the arithmetic operation of summing; calculating the sum of two or more numbers