Hypersonic wind tunnels operating at very low densities were developed starting in about 1960.低密度超音速风洞大约开始发展于1960年.It would reach hypersonic speeds -- five times the speed of sound.也就是说,要使飞机达到特超音速—即音速的五倍.FEM FCT is used ...
The paper has earned respect for its investigative journalism.这份报纸的调查性新闻报道为其赢得了尊敬。He founded the Centre for Journalism Studies at University College Cardiff.他在加的夫大学学院成立了新闻学研究中心。He made his living by a mixture of tutoring...