The lighter version used liquid hydrogen, the heavier used hypergolic propellants.较轻的推进器采用液态氢, 较重的采用自燃推进剂.Pressure - fed engines are particularly susceptible to dissolved gas in the propellants.挤压 式 发动机对推进剂中溶解的气体特别敏感.Thi...
Deliberate before you begin, then execute with vigour.著手前要深思熟虑,执行要果断有力。He was a man of extraordinary vigour and liberality of mind.他是个生气勃勃和思想非常开朗的人.A succinct style lends vigour to writing.措辞简练使文笔有力.His body lacks the bo...