What sort of commitments, if any, will the various less developed countries make in return for some of that money?

各个不同的欠发达国家如果做出承诺的话，需要做出怎样的承诺作为对这些资金的回报？

But, put together, the two studies suggest rotavirus vaccines can make a real difference in less developed countries.

但，加在一起，这两个研究提示轮状病毒疫苗在欠发达国家真的有差别。

Most people who live in less developed countries are quite poor.

生活在欠发达国家中的大部分人是十分贫穷的。

TiP:Less developed countries tend to be good places to meet other solo travelers.

小贴士：欠发达的国家是能遇到其他独自旅行者的好地方。