---
id: 5d822fd413a79914d39e98f2
title: Part 42
challengeType: 0
---
## Description
Add the new `bb1-window` class to the `bb1a`, `bb1b`, and `bb1c` elements. This will apply the gradient to them.
## Instructions
## Tests
```yml
tests:
- text: test-text
testString: assert($(".bb1a.bb1-window").length === 1 && $(".bb1b.bb1-window").length === 1 && $(".bb1c.bb1-window").length === 1);
```
## Challenge Seed
```html
freeCodeCamp Skyline Project
```