12. If he (to pollute) water, he (to do harm) to the environment. 13. Our streets (to be clean) if you (not to litter). 14. If Bob and Bill (to clean up) after picnics together with their friends, Ann (to invite) them to the party next Friday. 15. Kate (to meet) you, if I (to be) here tomorrow. 16. If people (to stop) throwing rubbish into the local river, clean water (not to be) a problem in this town. 17. They (to visit) London Eye if she (to come) to London next week. 18. I (not to buy a souvenir if the shop (to be ) closed next Wednesday. 19. Animals (not to be ) in danger if we (not to cut down) the trees. 20. You (to be ) healthy if you (not to eat) junk food. 21. If I I (to see) Jack tomorrow, I (to tell him about it. 22. They ( to pass) the exam if they (to work) hard.​

1. it (has been snowing) steadily the whole week and it is still (snowing) 2. we (have been climbing) for six hours already, but we (haven't reach) the top of the mountain yet. 3. the pain has already (gone) but the child is still (crying). 4. have the workers (been working) very hard these two weeks? they (were) busy with the interior decoration of the house. 5. he (has been solving) the crossword puzzle for an hour and he (says) he is about to solve it as he (is thinking) over the last word оf it 6. he (has been working) at the language all the time and (has made) great progress. his pronunciation is rather good, only a slight accent (remains). 7. не (has finished) the first part of his book and now he (is writing) the second. he (has been working) at his book for two years. 8. dusliri hoffman, who (plays) the hero, (is giving) a fine performance. 9. why is your hair wet? have you been (swimming)? 10. doctors and scientists have recently shown the benefit of fish in the diet

In today's world we encounter the technology at every step and everyone uses them. I think that technology makes our lives easier. Because we depend on them.Firstly, electronic gadgets make it easy to search for information,  for saving our time. For example, when we were leaving somewhere, we use the navigator to avoid getting lost in an unfamiliar place.Secondly, the technology enables us to communicate with each other at any distance. For example, e-mail allows us to quickly and cheaply send SMS to every corner of the earth. In addition, thanks to the Skype we can call anywhere and even see companion.On the other hand technology is not very safe and secure. They are often broken, can be lost or stolen.In conclusion, I want to say that technology is very important to us, so we must learn to master them.  It will be useful in the future.