The Valley of Vinales is a lush and fertile valley and one of Cuba's finest beauty spots.比尼亚莱斯谷草木繁茂，土地富饶，是古巴最美的风景胜地之一。Irregularly shaped brown or blue spots in the nail bed can be melanomas.甲床上不规则的棕色或蓝色点可能是黑索瘤.Secur...
As regarded its origin there were various explanations, all of which must necessarily have been conjectural.至于其来源,则有着种种解释, 当然都是些臆测.Theories about the extinction of dinosaurs are still highly conjectural.关于恐龙灭绝的理论仍然是带有很强的...
The forebody design a key issue for hypersonic airbreathing vehicle.前体设计是吸气式高超声速飞行器设计的关键之一.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.hypersonic aerodynamics高超音速空气动力学rarefied...