题目

How does the woman happen to know about the Garden Café? A . She is greatly encouraged. B . She got to know about it on line. C . The man talked about it to her. 答案：B北京奥运会主体育场的外形像鸟巢。硼烷的结构也像鸟巢，故称为巢式硼烷。五硼烷（B5H9）为传统火箭燃料，燃烧产物对环境污染小。下图是三种巢式硼烷，下列说法正确的是 [     ]A．图中M的名称为九硼烷 B．八硼烷的化学式为B8H12 C．硼烷有可能称为未来的清洁能源 D．2B5H9+12O25X+9H2O，则X中B的化合价为+5价