题目

请认真阅读下面短文，并根据所读内容在文章后表格中的空格里填入一个最恰当的单词。 注意：每个空格只填一个单词。 Imagine living in a country torn by war. Or maybe you live in a place where there are few jobs and little chance to earn a living. Your family decides to move — not to another town, but to another country. You and your family have become immigrants. People are called immigrants when they move to a foreign country to make their homes. People become immigrants for many reasons. The most common one is economic opportunities. Most 青藏地区青稞、小麦单产较高的主要原因是A. 海拔高、气温较低 B. 大气洁净、透明度好C. 河湖众多，雨水充足 D. 日照时间长，气温低，昼夜温差大