Complete the sentences with the correct form of the verbs from the list.

Input
Click on the gap and type the answer in
How to do exercises

Strike out
There are extra words in the sentence. Click on them to strike them out
How to do exercises
, , , , , , , ,
Radiation
was discovered
by Pierre and Marie Curie in 1900.
Experiments in the medical university

every day.
An important discovery

by Newton when he was resting under an apple tree.
The gravity theory

many times so far.
The telephone

in the 1870s.
New methods

nowadays by teachers and lecturers to organise the studying process better.
A lot of research must

to study side effects of new drugs.
Many tests and trials

to prove safety of a new method.
People can

to act as guinea pigs for medical experiment.

In Russia there are currently several types of schools, both public and private ones. Parents can optionally send their children to a gymnasium, lyceum or private school. Sometimes, when entering such educational institutions, children must take tests or exams. The standard of education is common to all schools, but schools themselves can choose teaching methods and textbooks. As a rule, before school, children go to nurseries and kindergartens, where they acquire teamwork skills, which makes studying at school easier.

А. 1. My mother has asked the brother to help her, but he hasn't helped her. 2. My aunt liked to play a violin when wasn't at home her husband. 3. My brother didn't want to open a door in the room therefore that he played computer games. 4. My friend hasn't invited us to herself on Sunday in view of the fact that she didn't want to prepare. 5. The other day we have received the letter from London, and my brother has translated him into Russian... B. 1. On Sunday we have gone to the country by train. 2. In the train we have met our colleagues from university. 3. We talked about work and our problems much. 4. When we have arrived to the country, we have seen ours the uncle and the aunt. 5. They have shown us the garden, and we have well spent time there. 6. Our aunt has made tea, and we had breakfast in a garden. 7. Then we worked a little and sang beautiful songs in a garden. 8. Then the aunt has given us vegetables from a garden for our parents. 9. We have taken vegetables and have gone home. 10. We have arrived home to 9 o'clock in the evening.