The word"hot"usually means"having a lot of heat."Many people think that"cold" is something completely separated from heat.But this is not true."Cold"simply means"having a little heat."
    Your life depends on heat.In fact，every living thing depends on it.Without heat，every living thing would be frozen to death.All living things get their heat from the sun，which provides the conditions in which life is possible.
    Since the very beginning of history，man has been able to make his own jye.aiat.He has been able to release the sun's heat that is hidden in things such as wood，coal and oil.And he has been able to use this heat.
    Heat has made civilization（文明） possible.With heat，man could melt metals.As man learned to use metals and fuels，industries grew.As a result，engines were invented.These are machines that change heat energy into mechanical energy.Engines can do the work of many men.Without engines，industrial civilization is impossible.
    Yet although the first engines were built in the 1716 century，men were still wondering about the nature of heat."What is it？"they asked.Not until the early years of the 19^th century did they find the right answer.

（1）What can we learn about"cold"and"heat"according to Paragraph 1？

C

C

A."Cold"has nothing to do with"heat".
B.Coldness and heat are two separate things.
C.Coldness and heat are related in some way.
D."Cold"is as important as"heat"to people.
（2）What's the main idea of Paragraph 2？

B

B

A.Life is better without heat.
B.Life is impossible without heat.
C.Life is better if there is more heat.
D.Life is impossible in the cold season.
（3）Which is the most important for industrial civilization according to the passage？

B

B

A.Metal.
B.Engine.
C.Fuel.
D.Heat.
（4）When did people find the nature of heat？

C

C

A.From the beginning of this century.
B.At the end of last century.
C.In the 19^th century.
D.In the 17^th century.
（5）What is the best title of the passage？

D

D

A.Industrial Civilization.
B.The Form of Heat.
C.Hot and Cold.
D.Nature of Heat.