题目

已知在热的碱性溶液中，NaClO发生如下反应：3NaClO→2NaCl+NaClO3。在相同条件下NaClO2也能发生类似的反应，其最终产物是    A．NaCl、NaClO                   B．NaCl、NaClO3      C．NaClO、NaClO3                 D．NaClO3、NaClO4 答案：B Often, when he ________ something useful, he wasted his time playing computer games. A. should be doing  B. must have done  C. should have been doing    D. shall be doing