These are all words for the lowest part of sth. 以上各词均指底部、最下部。

• bottom [usually sing.] the lowest part of sth 指底部、最下部：◆Footnotes are given at the bottom of each page. 脚注附于每页的下端。◆I waited for them at the bottom of the hill. 我在山脚下等他们。
• base [usually sing.] the lowest part of sth, especially the part or surface on which it rests or stands 指根基、基底、底座：◆The lamp has a heavy base. 这台灯的底座很沉。
• foundation [usually pl.] a layer of bricks, concrete, etc. that forms the solid underground base of a building 指地基、房基、基础：◆to lay the foundations of the new school 给新校舍打地基
• foot [sing.] the lowest part of sth 指最下部、底部：◆At the foot of the stairs she turned to face him. 她在楼梯底转过身来面对着他。

bottom or foot? 用 bottom 还是 foot？

• Foot is used to talk about a limited number of things: it is used most often with tree, hill/mountain, steps/stairs and page. Bottom can be used to talk about a much wider range of things, including those mentioned above for foot. Foot is generally used in more literary contexts. * foot 用于有限的一些事物，最常与 tree、hill/mountain、steps/stairs 和 page 等连用。bottom 适用的范围要广得多，其中也包括上面提到的与 foot 搭配的词。foot 一般用于文学性较强的语境中。

Patterns

• at/near/towards the bottom/base/foot of sth
• on the bottom/base of sth
• (a) firm/solid/strong base/foundation(s)

These are all words for the ideas or facts that sth is based on. 以上各词均指基础、根据。

• basis [usually sing.] a principle, an idea or a fact that supports sth and that it can develop from 指基础、要素、基点：◆This article will form the basis for our discussion. 这篇文章将作为我们讨论的基点。
• foundation [C, U] a principle, an idea or a fact that supports sth and that it develops from 指基本原理、基础、根据：◆Respect and friendship provide a solid foundation for marriage. 尊重和友爱是婚姻的牢固基础。◆The rumour is totally without foundation(= is not based on any facts). 这谣传毫无事实根据。

basis or foundation? 用 basis 还是 foundation？

Foundation is often used to talk about larger or more important things than basis. 与 basis 相比，foundation 常用以指更大、更重要的事物：◆He laid the foundations of Japan's modern economy. 他奠定了日本现代经济的基础。◆These figures formed the basis of their pay claim. 这些数字是他们要求提高工资的根据。

• base [usually sing.] an idea, a fact or a situation from which sth is developed 指根据、出发点：◆His arguments have a sound economic base. 他的论点在经济上有充分的根据。

Patterns

• a/the basis/foundation/base for/of sth
• a secure/solid/sound/strong/weak basis/foundation/base
• to form the basis/foundation/base of sth
• to be without basis/foundation