钢铁企业的能耗指标一般统一折算成生产每吨钢所消耗（）的千克数。
A.煤气
B.标准煤
C.重油
参考答案：B
Recently, I ___ my first horse ride in Lijiang, Yunnan Province __ I paid a visit to many local attractions
A．have had ; before
B．had ;when
C．had had; in which
D．was having; which
关于高倍镜使用的描述，错误的是[ ]
A．把视野调亮，图像才清晰
B．先在低倍镜下看清楚，再转至高倍镜
C．先用粗准焦螺旋调节，再用细准焦螺旋调节
D．高倍镜缩小了观察的视野，放大了倍数
