课堂中某些占优势的态度与情感的综合状态称之为( )
A．课堂规范
B．课堂气氛
C．课堂管理
D．课堂纪律
参考答案：B
(2013·福建毕业班质检)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
元曲四大家
