Use Present Perfect.1. We _______________ (talk) about the environment in our English class this week. 2. The air _________(get) worse and worse in the last twenty years. 3. That factory ______________ (pollute) the river. 4. I have read (read) your book several times.5. You ________________ (break) the glass again.6. We _______________ (see) him before.7. I _____________ (have) a snake