In AngularJS, expressions can be used within ___________ to dynamically assign classes or styles.

In AngularJS, expressions can be used within ngClass and ngStyle directives to dynamically assign classes or styles to HTML elements. The ngClass directive allows dynamic class binding based on expression evaluation, while ngStyle enables dynamic style assignment. This capability enhances the flexibility and responsiveness of AngularJS applications by allowing dynamic updates to the presentation layer based on changing data or user interactions.