读太阳系示意图，回答题。
与地球相比，天体甲没有生命存在的根本原因是（）
①没有适合生物呼吸的大气
②没有坚硬的地表
③距日较近，表面温度偏高
④没有昼夜更替现象
A.①②
B.③④
C.①③
D.②④
参考答案：C
解析：
根据图示甲位于距离太阳最近的位置，则表面气温很高，且由于质量、体积较小而导致了引力较小，而没有大气，故不能形成生命物质。
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| Around the world, people have different ideas about what good manners are. When you go to restaurants in different parts of the world, it's 1 to know the right and wrong things to do. For example, in China it's OK to 2 a lot of noise in a restaurant. In fact, if a restaurant isn't 3 or lively, you may think there's something wrong with it. However, in many western countries, restaurants are quiet places. If a table is too loud, other people who are eating there might even 4 to the owner of the restaurant. Paying the bill 5 also different from country to country. In China, one person usually pays 6 everybody. In western countries, one person pays if he or she is entertaining clients (宴请宾客), but 7 friends eat together, they usually share the cost. This is called "Going Dutch (均摊费用)". Also, when westerners pay the bill, they usually leave some money for the 8 .This is called"leaving a tip (小费)". Leaving a tip is thought to be polite. In the US, it's 9 to leave tips of 10％,15％,or 20％ of the bill, which is decided by how good the service is. Good waiters can make a lot of money! The way people eat food is different in the world, but you can 10 the same kind of food in many countries. Chinese and Italian food, for example, are popular all over the world. | |||
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伏，那么（ ）