题目

己知在碱性溶液中可发生如下反应：2R(OH)3+3C1O－+4OH－=2RO4n－+3Cl－+5H2O。则 RO4n－中 R 的化合价是 A. +7                        B. +6                    C. +5                        D. +4 答案：B—Do you think it was the supermoon that caused the earthquake on March 11,2011 in Japan?—________.It hasn’t proven itself true by scientists.A．Not in the least? B．Don’t mention itC．You can say that again? D．I expect so