1. In this way, students are encouraged to make revisions of the lessons.
If you ask a student to "make a revision" you are asking them to change the lesson! I imagine what you need is: "In this way, students are encouraged to revise what they have learned [in class]."
2.Weekly control exam is held in two weeks based on weekly assignments.
I don't understand this. How can a weekly exam be held in two weeks? If it's a weekly exam, it's held every week. If the exam is every two weeks, then it's a fortnightly exam.
3.Students are encouraged to do homework through this exam.
Students are encouraged to do homework in order to prepare for this exam. (Again, I'm not sure what you mean. They're not doing homework "through" the exam. Homework and the exam are two separate things.)
4.The necessary measures are taken after evaluating whether students understood reviewed subjects and followed them.
I don't think you need "and followed them". The necessary measures are taken after evaluating students' comprehension of the reviewed subjects. I assume you mean that after the exam, the teacher looks at how well each student did, determines which areas need extra work, and acts accordingly.
Student or Learner