题目

Bike-sharing has swept across China, with an increasing number of people choosing bike riding instead of driving. The bike that the service company provides has GPS or Bluetooth on it, and those bikes can be easily unlocked with a smart phone and left anywhere in public. Bike-sharing allows people to borrow a bike from one place and return it at another place easily.In some cities, we can see more and more people riding this kind of sharing-bikes. It’s very convenient to use the bikes if you have a smart phone. First, you have to download such an APP on your smart phone. Then what you need t已知S、Cr两元素的最高价均为+6，则下列粒子中，从化合价分析，可能存在过氧键（—O—O—）的是(    )A．B．C．D．