题目

Evergreen Teen Book Club Offer The Evergreen Teen Book Club invites you to join us and take full advantage of our limited-time introductory offer. If you join our club, you will receive a certificate for 3 free books. These are yours to keep, even if you decide to cancel your membership. However, if you decide to purchase just one book at the regular club price, you will receive a certificate for an additional book after your first order is placed. As our member, you can benefit from all of our super sales and our Bonus Program. You accumulate (积累) 2 bonus points with each cash purc已知，A、B、C、D四种物质之间存在以下转化关系．其中C是单质，D是相对分子质量最小的氧化物．试回答（1）写出A、C、D三种物质的化学式：A______、C______、D______．浅绿色溶液B中溶质的化学式______．（2）写出C→D的化学方程式______ 2H2O