我知道这是一个被多次讨论的问题。可我看了其他帖子，还是不能够理解。希望老师指点迷津。

如果than在句子中做代词使用，下面的句子是否正确呢？

A study commissioned by the Department of Agriculture showed that if calves exercise and associate with other calves, they require less medication and gain weight more quickly than those raised in confinement.

In Japan elderly people are treated with far greater respect than they are in most Western countries.