______ is practiced to some extent by the adherents of every religion. It often requires abstinence from food, drink, or sexual activity, as in fasting or celibacy and it may also require physical pain or discomfort, such as endurance of extreme heat or cold or self-punishment.

A．Extravagance

B．Opulence

C．Deterioration

D．Asceticism

右图是胡萝卜在不同的含氧情况下从硝酸钾溶液中吸收K+和NO3-的曲线。影响A、B两点和B、C两点吸收量不同的因素分别是（）

A.载体数量、能量

B.能量、载体数量

C.载体数量、离子浓度

D.能量、离子浓度