1, an infinite set contains a set of infinite elements.

2. A finite set contains a set of finite elements.

3. Image transformation includes images: translation transformation, expansion transformation, symmetry transformation and folding transformation. 4. Multiple monotonous intervals cannot be connected by "or" and ","and can only be separated by commas.

5. If a function is a combination of some basic functions through four operations, then its domain is a set of values of x, which makes all parts meaningful.