X. Translate the words in brackets into English.

IX. Fill in the blanks with the right prepositions.

VIII. Fill in the blanks with the verb in the right tense-form.

1. Alexander Fleming (find) some mould growing on a laboratory dish which he absent-mindedly (leave) on a window-sill.

2. Millions of lives every year (save) thanks to modern antibiotic drugs based on penicillin.

3. British military scientists (discover) the radar during the war while they were trying to find a death ray.

4. Teflon (use) in non-stick frying pans and space vehicles.

5. Scientists (do) another experiment and they happened to taste one of the by-products of one substance which they found to be sweet.

6. He always (chew) gums!

7. Du Pont scientists discovered that a plastic coating (form) on their equipment and this (be) unaffected by heat and it (be) also very slippery.

8. Stick-on notes already (use) by us for some years.

1. Most important discoveries … the world … science and technology came … by some sort of lucky accident.

2. Alexander Fleming found some mould growing … a laboratory dish which he had absent-mindedly left … a window-sill.

3. Now all the sea and air transport depends … radar … navigation and safety –and armies depend … it … defence.

4. Radar was discovered … the war.

5.Teflon is a substance which is used … non-stick frying pans.

6. Teflon was discovered … accident … a laboratory … DuPont scientists, who were doing research into gases to use … refrigerators.

7. Some of artificial sweeteners are thousand times … sweet … sugar.

8. Chewing gum was discovered while scientists were looking … a substitute … rubber.

1. Most important (открытий) in the world of science and technology (появились) by some sort of (счастливого случая).

2. Alexander Fleming (по рассеянности) left some mould on a window-sill and later found that it stopped the spread of bacteria, which is the cause of illness like pneumonia.

3. Radar was discovered during the war while British (военные ученые) were trying to find a death ray, which was some sort of radio wave that could be used to kill people.

4. Teflon was discovered by accident in a laboratory by DuPont scientists, who were doing (исследования) into gases to use into refrigerators.

5. Scientists were doing another experiment and they happened (попробовать) one of the (побочный продукт), which they found to be sweet, so artificial sweeteners appeared.

6.Chewing gum was discovered while scientists were looking for (заменитель) for rubber.

7. A researcher was doing into adhesive and glue, and discovered (вещество) that was quite sticky but it wouldn’t (приклеиваться) permanently to anything and it didn’t (оставлять следы) on the surface.