1. The difficulty of the problem is manifest.
    这问题的困难是明显的。

2. The fact of first-rate importance is the predominant role that custom plays in experience and in belief, and the very great varieties it may manifest.
    最重要的是，风俗在实践中和信仰上所起的举足轻重的作用，以及它所表现出来的极其丰富多采的形式。

3. Surely because progress of a particular kind is actually taking place around us and is becoming more and more manifest.
    无疑是因为有一种特殊的进步实际上正在我们周围发生，而且变得越来越明显。