There exist two kinds of solitude:one is relative, the other is absolute.
存在着两种孤独：相对意义上的孤独，和绝对意义上的孤独。
There exist two viewpoints to the use of calculators in Mathematics teaching.
当前对于计算器在中学教学中的使用主要有两种观点。
There exist two theories about the mechanism of the attention choice:early choice or late choice.
关于注意的选择机制，有两种不同的理论，一种是早期选择机制，另一种是晚期选择机制。
Finally, for reading environment variables there do exist two functions.
最后，对于读取环境变量，有两个函数。
But the two belong to different language phenomena and there exist some differences.
但两者属于不同的语言现象，因此又有区别。
Modern medicine has proved that there exist more than two genders of male and female.
现代医学证明，性别并非只有“男”、“女”两种。
However, there still exist some different aspects between the two optimization methods.
然而，需要注意的是两种优化方法各有特点。
However, there still exist some different aspects between the two optimization methods.
然而，需要注意的是两种优化方法各有特点。
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