Предмет: Биология, автор: soom

какую роль играет вода в клетке

Ответы

Автор ответа: lelik0897

Вода придаёт клетке объем и упругость, осуществляет осмотические явления, способствует теплорегуляции клеток, является средой хим. реакций, является источником кислорода в процессе фотосинтеза у растений, осуществляет транспорт веществ=)

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Conductors.

1.Text.

According to their conductivity all materials are divided into conductors,

insulators and semiconductors. Conductors allow electricity to pass through

them; insulators do not.

Conductors are materials having a very high conductivity. A conductor owes its

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3.Вопросы по тексту:

1. Into what groups are materials divided?

2. What do conductors do?

3. What materials are common conductors?

4. Are their coefficients of resistance different?

5. What metals have high mechanical strength?

6. What coefficient of resistance has carbon?

7. What materials are commonly used to produce wire conductors (brushes,

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4.Переведите словосочетания:

a) wire strength; semiconducting material; air insulator- carbon brushes;

b) changing strength — changed resistance; insulating materials — insulated

conductors; heated brushes — heating sources.

c) common wire strength; highly conductive copper wire; commonly produced

wire brush; parallely connected circuit elements; commonly produced heaters.

d) any value of resistivity; rather low melting point.

5.Используйте в ответах: “certainly”, “I suppose”, “I don't know”.

1. Is bronze used to produce conductors?

2. Has copper a positive coefficient of resistance?

3. Have metals (steel, copper, iron) good mechanical strength?

6.Test. Choose the correct variant:

1. All materials are divided into ...

a) conductors and semiconductors;

b) conductors, insulators and semiconductors.

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a)high mechanical strength;

b)low mechanical strength.

3. Carbon has ...

a)a positive coefficient of resistance;

b)a negative coefficient of resistance.

4. Copper is commonly used to produce ...

a)heaters;

b)brushes.

7.Используйте английские слова вместо русских.

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e) Conductors are divided into groups (в зависимости от) their resistivity.

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