Nitrogen

Nitrogen (to play - Present Indefinite Active) a very important role in nature. As a constituent of proteins, it (to find – Present Indefinite Passive) in the body of every plant and animal. Proteins (constitute – Present Indefinite Active) the most important parts of cells, namely, the protoplasm and the nucleus. The wonderful changes which proteins (to undergo – Present Continuous Active) in plant and animal cell form the basis of all vital processes. Thus life is impossible without proteins.

Nitrogen may be prepared: 1) from air by removal of oxygen, 2) from nitrogen compounds. Nitrogen which (to obtain – Present Indefinite Passive) from air is called atmospheric oxygen. Nitrogen obtained from compounds (to call – Present Indefinite Active) chemical nitrogen. Pure nitrogen (to be – Present Indefinite Active) a colourless, odourless gas, very slightly soluble in water. It (to be – Present Indefinite Active) a little lighter than air, the weight of 1 liter is 1,25gr. When nitrogen (to cool – Present Continuous Passive) for a long time under high pressure it (to become – Present Indefinite Active) a liquid which boils at – 195,8 and solidifies into a snow like mass at 210°C. Nitrogen (to be – Present Indefinite Active) an inert element which at ordinary temperature is almost incapable to form compounds. While it (to heat – Present Continuous Passive) it (to combine – Present Continuous Active) quite readily with some metals, such as lithium, magnesium, titanium. Finally, at very high temperature nitrogen (to combine – Present Continuous Active) directly with oxygen and hydrogen.

Part II

Speech patterns

DIALOGUES

Present Indefinite and Present Continuous for the Future Actions.

Saying good-bye.

I.Read the dialogues in pairs.

I

A: I’ve come to say good-bye.

B: When are you off?

A: I’m flying home on Sunday.

B: Good-bye then, and all the very best.

A: Cheerio. Say good-bye to the rest of the family for me, won’t you?

* When are you off? I’m flying home on Sunday.

Здесь и далее формы настоящего неопределенного и настоящего длительного времени употребляются в значении будущего времени.

II

A: I’d like to say good-bye to you all.

B: What time are you going?

A: My train leaves at 8 p.m.

B: Good-bye and have a good journey.

A: Good-bye. Remember to look me up if ever you are in Rome.

III

A: I’m ringing to say good-bye.

B: When are you setting off?

A: I’m catching the 11.35 boat.

B: Cheerio and don’t forget to keep in touch.

A: Good-bye. Thanks for everything.

IV

A: I’ve just called in to say good-bye.

B: What time are you leaving?

A: I’m going to try to get away by ten.

B: Good-bye. Remember me to your parents.

A: Good-bye. See you next year.

to be off	отправляться;
all the best; cheerio	всего хорошего;
remember me to your parents	передай привет своим родителям;
the rest	остальные;
journey	путешествие;
to look me up	навестить меня
to set off	уезжать, отправляться;
I’m catching the 11.35 boat	я отправляюсь пароходом в 11.35;
to keep in touch	зд.: сообщить о себе (досл.: держать связь);
to call in	заходить, забегать;
to try to get away	пытаться уехать.

II. Compose your own dialogues about your plans for the nearest future. Use word combinations in the box and present continuous tense to express future.