Using Conditional 2 or 3.
1. The environment (be)____ much cleaner if people (not use)____ so many chemicals.
2. I (help)____ if I (have)___ more time.
3. If people (not drop)____ so much litter, our streets (be)____ so tired.
4. I (go)____ to the cinema tonight if I (not be)____ so tired.
5. If I (know)____ you were ill, I (visit)____ you.
6. She (not disturb)____ if it (not be)____ that important.