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生产力所体现的关系是人类社会和自然界之间的关系。 ()
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货币政策是一个国家的政府改善宏观经济运行状况的重要手段。 ()
出于商业秘密的考虑，基金管理人、代销机构对不同投资人适用不同费率，可以不进行公告。()
subject to satisfactory arrangements ______terms and conditions,we should be pleased to act as your sole agent.
The concept of escape velocity applies to objects as small as atoms and molecules. The earth's atmosphere is composed primarily of oxygen and nitrogen, and it contains practically no trace of hydrogen or helium, the lightest elements. All the atoms of a gas travel in random motion at very high speeds, and the less massive atoms and molecules travel at the greatest speeds. In fact, the lighter gases go so fast that their speeds are greater than the critical speed of 11.2 kilometers per second. Thus they have long ago left our comfortable home and are now wandering through space in search of a more hospitable gravitational field.
The moon has a weaker gravitation field than the earth. The escape velocity of an object on the moon is about 2.4 kilometers per second, and even the heavier gases have enough speed to escape the moon. This explains why we find no atmosphere there; any gases that may be released near the moon quickly escape.
Only when a ball exceeds 11.2 km' per second can it ______.
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