名词

1. 扩张;扩充;扩大;发展
Expansion is the process of becoming greater in size, number, or amount.

1. the act of increasing (something) in size or volume or quantity or scope

Synonym: enlargement

2. adding information or detail

Synonym: expanding upon

3. a discussion that provides additional information

Synonym: enlargementelaboration

4. a function expressed as a sum or product of terms

e.g. the expansion of (a b)^2 is a^2 2ab b^2