Here are some of the help online for young people on test revisions (复习).
BBC Bitesize is one of the best websites (网站) when preparing for a test. Whether you're in England, Scotland, Wales or Northern Ireland, you can choose a subject and see the articles and videos on each topic, such as creative writing and the food chain (食物链).
The Maths Guy on a YouTube channel can be really useful. Its videos explain different maths topics clearly. It also has weekly challenges to test what you've learned.
Duolingo Math is one of the newest and leading mobile apps to help you revise maths. It's made by the company behind the language-learning app Duolingo, and it has lots of short exercises to help you have new maths ideas. Duolingo Math is only available for Apple devices.
Squeebles is a fantastic app for revising spellings, especially difficult words. It is available (可用的) for both Apple and Android devices.