题目

某有机物的结构如下图，当Na、NaOH、NaHCO3分别与等物质的量的该物质恰好反应时，则Na、NaOH、NaHCO3的物质的量之比为 A．3∶3∶2      B．3∶2∶1        C．1∶1∶1      D．3∶2∶2 答案：BEnshi is becoming a tourist city． _________ people come here during the holidays every year． A．Thousand of                              B．Thousands of C．Five thousands of                       D．Five thousands