. You can’t imagine _______ when they received those nice Christmas presents.

A．how they were excited

B．how excited they were

C．how excited were they

D．they were excited

国家运用财税、价格等政策，支持推广电力需求侧管理、（）、节能自愿协议等节能办法。

A.合同能源管理

B.能源需求管理

C.节能服务机构

D.能源效率标识