integral of generalized momentum

例句：

1. 1. The total cost of the projectis $50,000.
   这个项目的总成本是5万美元。
2. 2. The integralpart of the problem is to find asolution.
   问题的核心在于找到解决方案。
3. 3. The wholeprocess took less than an hour.
   整个过程不到一个小时。