Am I ready to study in English?

Self-assessment exercises: reading and understanding
The homework that Jim passed in his class last monday.. and I didn't forget.. see my result:

Task 3: Science: Keeping our water clean
1- A (correct)
2-A (correct)
3-B (correct)
4-A (incorrect)
5-A (correct)
6-B (correct)

Self-assessment
It was not a problem at all. I understood the tasks and got most of them right.