I signed up for a refresher course in Spanish before my trip to Mexico.
Employees are encouraged to take a refresher course in customer service skills annually.
The company offers a refresher course workshop for employees who need to update their knowledge on new software.
After years of not playing the piano, I decided to take a refresher course class to brush up on my skills.
The university offers a refresher course program for students who want to review material before taking advanced courses.