为什么中国不能制造他们自己的空中防御系统？

Why China couldn't make their own air defense systems?

youdao

在摧毁打击利比亚空中防御系统方面，美国是占据领先优势的。

The United States took the lead in knocking out Libyan air defenses.

youdao

他那个时候并不知道，半自动地面防空警备系统是冷战时期美国空中防御系统的重要组成部分，但它依然给他留下了深刻的印象。

He didn't realise at the time that SAGE formed an important part of America's air defence systems during the Cold War but it still made an impression.

youdao