Which is not contained by DOM level 1?

DOM Level 1 primarily provides a map of an XML document, allowing developers to navigate, add, modify, or delete elements and content in the document. It includes two modules: the Core, which provides a basic document model, and the HTML, which extends the Core to include HTML-specific objects and methods.

However, DOM Level 1 does not contain the following:

1. Event handling: DOM Level 1 does not provide any built-in method for handling events like clicks or key presses. This feature was introduced in DOM Level 2 with the Events module.

2. CSS object model: DOM Level 1 does not include any methods or objects for dealing with CSS styles. This feature was also introduced in DOM Level 2 with the Style module.

3. XML namespaces: DOM Level 1 does not support XML namespaces, which allow for the qualification of element and attribute names by associating them with namespaces identified by URI references. This feature was introduced in DOM Level 2.

4. Traversal and Range: DOM Level 1 does not provide any methods for traversing the document tree or working with ranges of nodes within the document. These features were introduced in DOM Level 2 with the Traversal and Range module.

So, to answer your question, DOM Level 1 does not contain event handling, CSS object model, XML namespaces, and traversal and range features.