原文：

中国经济这些年确实发生了很大的变化，我们的经济总量跃居到世界第二位，但是我们一直清醒地认识到中国人口多、底子薄、发展不平衡，依然是一个发展中国家。

参考译文：

It is true that recent years have witnessed major changes in China’s economy. Now the Chinese economy has become the second largest in the world. But at the same time, we are also fully aware that China remains a developing country with large population, weak economic foundation and uneven development.

词汇：

跃居到世界第二位become the second largest in the world

清醒地认识are fully aware

翻译笔记：

“中国人口多、底子薄、发展不平衡，依然是一个发展中国家”译文用with带名词结构

底子薄指经济基础薄，故翻译为“weak economic foundation”

译文用英文名词短语来表达“中国人口多、底子薄、发展不平衡”这些动宾结构，这种用法也比较常见。