3. Fill in the blanks with the correct modal verb from the box. Use each verb only once. must, mustn't, have to, should, can, can't, could 1. When I was only five years old, I ____________ already swim across the whole lake. 2. You ____________ be late for the exam tomorrow; the doors close at 9:00 sharp! 3. I think you ____________ adopt a pet from a shelter; it's a very worthwhile thing to do. 4. In many schools, students ____________ wear a uniform. It is a strict rule. 5. I ____________ speak Chinese, but I am studying hard to learn it. 6. To be a successful teacher, you ____________ respect your students and lead by example. 7. My brother is very talented; he ____________ construct amazing models out of wood.