题目

What time is it？Most people are pretty accurate in their answer. And if you don’t know for sure, it’s very likely that you can find out. There may be a watch on your wrist; there may be a clock on the wall, desk, or computer screen; or maybe you’re riding in a car that has a clock in the dashboard . Even if you don’t have a timepiece of some sort nearby, your body keeps its own beat. Humans have an internal clock that regulates (调节) the beating of our heart, the peace of our breathing, the discharge (排出) of chemicals within our bloodstream, and many other bodily functi若函数对定义域R内的任意都有=，且当时其导函数满足若则 A．     B．   C．     D．