1)b2)b3)a4)c5)b6)c7)a8)a9)c10)b4-е задание1. Neither he nor his sister had not come for the evening.2. And a friend of mine , and I have done everything possible to help him .3. He never knew how to sing or dance.4. I would like to spend a vacation in the Crimea and the Caucasus .5. Do not worry , either Kohl or Peter know his address.6. And my friend and I will help him .