Meaning: This sentence tells us that the teacher gave the students a test that was hard to do or understand.
Choice of Words: The word "teacher" means a person who teaches students in a school. The word "gave" means to transfer something to someone. The word "students" means people who are studying at a school. The word "difficult" means hard to do or understand. The word "test" means a set of questions or tasks that are used to measure someone's knowledge or skill.