原子序数依次增大的五种元素A、B、C、D、E位于周期表的前四周期．A基态原子的2p轨道上有2个未成对电子；C的最外层电子数是次外层电子数的3倍，C与D同主族且相邻；E位于周期表的ds区，最外层只有一对成对电子．请回答下列问题：
The computer, help we human beings have stepped into the information age, should be regarded as one of the most important inventions in the 20th century.
873÷46=____......____
如果|a|=6，|b|=5，且a＜b，请你求出a+b的值．
