You are to write a composition in no less than 400 words, on the above topic. Marks will be awarded for content, organization, grammar and appropriateness. Failure to follow the above instructions may result in a loss of marks.
Write your composition on ANSWER SHEET FOUR.
The f【74】similarity of liquids and gases becomes clearly apparent when the temperature and pressure are raised somewhat. S【75】a closed container partially filled with a liquid is heated. The liquid expands, or in other【76】, becomes less dense; some of it evaporates. In contrast, the vapor above the liquid surface becomes dense as the evaporated molecules are added【77】it. The combination of temperature and pressure【78】which the densities become equal is c【79】the critical point. Above the critical point the liquid and the gas can no longer be dis【80】; there is a single, undifferentiated fluid phase of uniform. density.
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目前,我国农村留守儿童数量较多,你认为留守儿童会造成哪些危害,应该怎样解决?
Tiger snakes got their name from their ______.