选磨的基本原则是（）

A . ['['前伸https://assets.asklib.com/psource/2015092416532232721.jpg 有早接触时，磨改下前牙切缘B . 前伸https://assets.asklib.com/psource/2015092416532232721.jpg 及正中https://assets.asklib.com/psource/2015092416532232721.jpg 有早接触时，磨改上前牙斜面C . 正中https://assets.asklib.com/psource/2015092416532232721.jpg 及侧向https://assets.asklib.com/psource/2015092416532232721.jpg 有早接触，磨改过高牙尖D . 用咬合纸检查咬合，凡蓝色较深者应磨改E . 先检查并磨改正中高点，再检查磨改非正中https://assets.asklib.com/psource/2015092416532232721.jpg 高点

A . 前伸https://assets.asklib.com/images/image2/201704230926417016.jpg 有早接触时，磨改下前牙切缘B . 前伸https://assets.asklib.com/images/image2/2017042309264943464.jpg 及正中https://assets.asklib.com/images/image2/2017042309270127313.jpg 有早接触时，磨改上前牙斜面C . 正中https://assets.asklib.com/images/image2/2017042309270872726.jpg 早接触，侧向https://assets.asklib.com/images/image2/2017042309271884445.jpg 有https://assets.asklib.com/images/image2/2017042309270872726.jpg 干扰D . 用咬合纸检查咬合，凡蓝色较深者应磨改E . 先检查并磨改正中https://assets.asklib.com/images/image2/2017042309270872726.jpg 高点，再检查磨改非正中https://assets.asklib.com/images/image2/2017042309270872726.jpg 高点