The net result is a continuous flow of gas, starting as hot gases in intergalactic space and ending as a drizzle of cool gas called a "cooling flow," falling into the central galaxy.
Graduate students starting work on their dissertations often ask me for strategic advice. What are the hot research areas?
许多开始写博士论文的研究生总要我给他们些战略性建议，比如现在热门的研究领域是什么？
3
Most people live on the four largest. The Hawaiian Islands were formed starting millions of years ago by hot liquid rock flowing from undersea volcanoes.