我研究类似的问题七年之久，期间我采访过一些包办婚姻的夫妻，他们彼此之间的爱意随时间慢慢的增长。

Having studied such matters now for seven years, in part by interviewing people who are in arranged marriages in which love has grown over time, I answered as follows.

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我在七年前到访德国时，遇到了一位官员，他向我解释说，德国有一个完美的办法来解决经济问题。

Seven years ago, when I was visiting Germany, I met with an official who explained to me that the country had a perfect solution to its economic problems.

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The next phase, concrete operations, from seven to twelve, you can solve the conservation problem, but still you're limited to the extent you're capable of abstract reasoning.

下一阶段,具体运算阶段,七到十二岁,儿童可以解决守恒问题,但儿童的抽象推理能力仍然有限

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