题目

A元素的原子最外层的电子数是a，次外层电子数是b；B元素的原子M层电子数是（a－b），L层电子数是（a＋b），则A、B两种元素形成化合物的化学式可能表示为 A.B3A2               B.BA2                           C.A3B2                   D.AB2 答案：BLet's ________ and ask him to ________ his dog.A.wake up him; look atB.wake him up; look forC.wake him up; look upD.wake up him; look like