血管周围细胞的营养不足,引起外膜的变性.Inadequate cell nutrition around vessels causes degeneration of tunica adventitia.假性动脉瘤一词用于只有一层动脉外膜的动脉瘤.A false aneurysm is the term applied when only the adventitia is present.心脏的外表面是由另一层结缔组织, 即心外膜所覆...
30 percent of reptiles, birds, and fish are currently threatened with extinction.目前，30%的爬行动物、鸟类和鱼类面临灭绝的危险。The rate of inflation is running at about 2.7 percent.通货膨胀率大约为2.7%。Last year, economic growth tailed off to below ...