In Russian write a content-based summary of the text you have translated

Make a reverse written translation (from Russian into English) of your summary.

30. Find more information about classification of materials based on other principles and tell your group mates.

UNIT IV

MATTER, ELEMENTS AND ATOMS

Language Work

Past Simple

Affirmative

I/we/you/they/he/she/it

carried out/turned off/left

For example:

· Alex carried out the experiment yesterday.

· They turned the gas off several hours ago.

The past of be (am/is/are) is was/were:

I/he/she/it	was/wasn’t		was	I/he/she/it?
we/you/they	were/weren’t		were	we/you/they?

For example:

· Physics was my favourite subject at school.

· In the 19^th and early 20^th century electricity wasn’t a part of the everyday life of many people.

· Were you interested in electronics earlier?

· There were a lot of electrical devices in the laboratory.

Negative (with the auxiliary verb)

I/we/you/they/he/she/it

didn’t

carry out/turn off/leave

For example:

· Alex didn't carry out her instructions precisely.

· The student left the laboratory, but he didn’t turn off the light.

Negative (with no auxiliary verb)

For example:

· We could not carry out more research.

· I had no time to finish my test.

· You were not a specialist when you studied at the University.

Questions (with the auxiliary verb)

Did

I/we/you/they/he/she/it

carry out?/ turn off?/leave?

For example:

· Did Alex carry out the experiment yesterday?

· Did you turn off the water supply before carrying out repairs?