Disadvantages and advantages of using a cow tissue heart valve rather than a human valve

Advantages of tissue valves compared to mechanical valves include the avoidance of lifelong warfarin therapy to prevent the development of blood clots. A disadvantage is their relatively poor durability compared to mechanical valves, with many requiring a re-operation in 10 to 20 years.

the virginia plan called for three branches of government and two houses of congress. representation in each house would be determined by population. the new jersey plan called for three branches of government and a single house of congress. each state would have an equal vote.

b. martin luther king jr. wrote and spoke "i have a dream"

explanation:

i know this 100 percent is correct   b. is the best one. < 3