题目

如果两个数的和为0，那么这两个数           （   ）A．都等于零      B．互为相反数      C．互为倒数     D．一定是一正一负  答案：B解析:略 ----- Hi, Mark. How was the musical evening? ----- Excellent! Ales and Andy performed _________ and they won the firs prize. A. skillfully                   B. commonly                      C. willingly           D. nervously