问题
选择题
It is said that sixty percent of all energy ________ in the world today is being lost as waste heat.
A．produced
B．producing
C．to produce
D．having produced
答案
答案：A
A 句意：据说现在世界上被生产的所有的能源中有百分之六十都被作为余热丢失掉了。本题考查非谓语动词作定语，被修饰词energy与produce之间是逻辑上的被动关系，四个选项中只有A项表示被动，故选A。