Задание 10 ( ). Вставьте this, these, that, those, используя подсказки. Напишите предложения полностью. Обратите внимание на пример:
These are toys. (Вблизи)
That is a chair. (Вдали)
are computers. (Вдали)
is a desk. (Вблизи)
is a radio. (Вблизи)
are cars. (Вдали)
are trains. (Вблизи)
is a tea set. (Вдали)
2. The author gives many interesting facts concerning the properties and peculiarities of phosphorus and compares it with (w/) nitrogen.
3. Firsly, phosphorus and nitrogen have much in common, but they also differ greatly.
4. While nitrogen is quiete inactive under ordinary conditions, phosphorus reacts rapidly both w/ metals and non-metals.
5. At ordinary temperature, nitrogen is a gas, and phosphorus is a solid.
6. Secondly, phosphorus has the following properties:
- it is almost insoluble in water;
- it dissolves in many solvents.
7. The article goes on that phosphorus exists in several aliotropic forms, only 2 of them are of general interest. One is white phosphorus.
8. The most striking property of white phosphorus is its activity w/ oxygen.
9. It is very combustible, that's why it must be left under water.
10. The author gives some measures of precaution while handling white phosphorus.
11. They are as follows:
- never handle white phosphorus w/ bare hands;
- always remember that it's very poisonous, it may cause chronic poisoning.
12. In the conclusion, it should be mentioned that red phosphorus is a more stable form. It isn't so combustible, but the products formed are the same produced by white phosphorus.
That's about all;-)