1. Choose a larger training institution with long online training experience.

2. The teachers of the course have strong professional background and rich training experience.

3. The course content should be advanced and the learning process at each stage should be grasped.

In addition to listening to extracurricular activities, candidates should consolidate their knowledge by doing problems. Therefore, the corresponding supporting materials should be complete, such as exercises and summary materials.

Of course, after-sales service is very important. There will be many problems in the learning process, and teachers must answer them.