Question

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.

Answer 1

1. would be, didn't use
2. would help, had 
3. didn't drop, would be ( здесь, похоже, неправильно задание дано. Должно быть  much cleaner. )
4. would, weren't
5. had known, would have visited
6. wouldn't have disturbed, hadn't been 

Answer 2

Using Conditional 2 or 3

1. The environment would be much cleaner if people did not use so many chemicals.2. I would help if I had more time.3. If people did not drop so much litter, our streets would not be so dirty.4. I would go to the cinema tonight if I were not so tired.5. If I knew you were ill, I would visit you.6. She would not disturb if it were not that important. Please note that the sources provided are not directly related to the specific sentences in the question. However, the usage of conditional 2 and 3 is a common grammatical structure in English.