When we see photographs of starving children, its hard to say that we should spend billions of dollars on space exploration. But thats just what we should do. Children dont need to be starving, but we do need to explore space. Right now, we have enough money to feed every person on Earth. Children are starving because of mismanagement of resources and simple human greed. Those are problems we can solve right here on earth. That shouldnt stop our need to find out whats beyond our own solar system. We may never make contact with whatever other species there may be out there in space. Even so, there are still two very practical and positive consequences of space exploration. One is a certainty and the other is a possibility. The certainty is medical research. Yes, we can conduct research here on earth. But much of the research done in space, for example, on the effects of gravity on bone marrow, is making a difference in medicine here on Earth. When we do research in space, we also learn more about space exploration. Also, many of the inventions that were developed for space travel have been adapted to good use on Earth. The possible consequence of space exploration is finding another planet human beings can colonize. Overpopulation is a huge problem on our planet. People are living longer, more healthful lives, and thats a good thing. But it means there are fewer people dying and more people being born. Eventually well have less space, fewer resources, and major distribution problems. If we can find another planet to live on, we can relieve the problems of overpopulation on our planet. Its a tragedy that there are human beings suffering on Earth. However, if we wait until everyone has a perfect life, we will never explore spaceand that , too, would be a kind of tragedy.
go on doing/to do的区别
forget doing/to do的区别
连词+分词(短语)的语法应用
不定式中省略to的情况
用于现在完成时的句型
过去进行时的应用
一般将来时的用法
With的复合结构作独立主格
stop doing/to do的区别
过去完成时的应用
不定式的时态和语态
动词不定式的否定形式
不用进行时的动词
cease doing/to do的区别
used to / be used to的区别
分词作表语的语法应用
try doing/to do的区别
be going to / will的区别
分词作插入语的语法应用
begin(start) doing/to do的区别
分词的语态
现在完成时的定义
一般现在时表将来的情况
mean to doing/to do的区别
动名词与不定式
用现在进行时表示将来的用法
分词作补语的语法应用
不定式的特殊句型too…to…
过去分词作宾语补足语的语法解析
be to和be going to的区别
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