Plastic heart valves and other human "spare parts" have __________ many recent developments in surgery.A) been possible B) become possibleC) been made possible D) made possible

Plastic heart valves and other human spare parts have __________ many recent developments in surgery.A) been possible B) become possibleC) been made possible D) made possible desecribe the function of atria,ventricles,valves,and the septum in the human heart.科学 plastic plastic plastic plastic plastic plastic plastic 英语翻译1.Closure of the valves of the heart produces mechanical vibrations which are audible at the chest wall as the heart sounds.The first heart sound is caused by the closure of the atrioventricular valves and so marks the beginning of ventri manifold valves是什么意思 the recognized causes of heart disease include the damage of the heart muscle or valves because of a congential defect or inflammation and the damage associated with various viral,bacterial,fungal,rickettsial or parasitic disesses.3835 Upper Plastic Upper Plastic plastic surgery plastic stretch plastic是什么意思 plastic是什么意思 Free plastic