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 ...
Congress is empowered by the Constitution to make laws.国会由宪法授予制定法律的权限.The new law empowered the police to search private house.新法律给予警察搜查私人住宅的权利。The courts were empowered to impose the death sentence for certain crimes.法院...