At the heart of the

At the heart of the phenomenon lie tiny marine microorganisms called phytoplankton.

这种现象的核心是被称为浮游植物的微小海洋微生物。

At the heart of the debate over illegal immigration lies one key question: are immigrants good or bad for the economy?

关于非法移民的争论的核心是一个关键问题：移民对经济是好还是坏？

For a while it looked as though the making of semiconductors, which America had invented and which sat at the heart of the new computer age, was going to be the next casualty.

有一段时间，由美国创造的、处于新计算机时代核心的半导体制造业似乎将成为下一个受害者。