Alternative questions 1. He is a policeman.
2. They are drivers.
3. We like basketball.
4. He likes volleyball.
5. He is reading a newspaper.
6. They are listening to music.
7. He has got a green balloon.

1) мы знаем, что он работает над проблемами в области космической связи.(его работа связана с проблемами).

2) если вы сделаете даже малейшую ошибку в компьютерном языке, разговор ломается и вы должны идти в начало.( наверное, имеется ввиду, ошибка в алгоритме, программа рушится и надо начинать сначала? )

3) читальный зал библиотеки конгресса - это огромная коллекция справочников.

thank you. i missed my friends. i received invitation from ann. this letter was fun. i wish  you lucky. george was picking plums. you can find such berries everywhere. we shut gathering of information about an object. he knows the woods, and we often go for mushrooms.  i was  able to make  my own sentences. there are so many beautiful pictures in the tretyakov art gallery! the witness recognized the suspect. i"m really sorry. you'd better have that bad tooth pulled out.    i am very glad to see you. tom is a great asset to the basketball team. they gave up the idea of selling their car. it was good. the boy is tike (грубиян). dear friend, we have just received your letter.

корова змея     чай     кофе     лимон   сахар     люстра

cow         snake   tea     cofee     lemon   sugar       chandelier

1. when he  graduates    from the university, he will become a good specialist.

2. if you  prepare   the report in time, you will take part in the conference.

3. when i  am 18, i  *ll  take part in the elections.

4. we *ll  revise the rules in some days.

5. if you  come to the lecture, you will learn many interesting things.