使用显微镜时,在镜筒下降过程中,眼睛应注视
A.目镜
B.反光镜
C.粗准焦螺旋
D.物镜
答案:D
镜筒下降,以防物镜压碎装片,损害镜头,所以眼睛要注视着物镜。
When Mom looked back on the early days of their marriage, she wondered how they had managed with
_____ money. [ ]
A. so few
B. such few
C. so little
D. such little
()矿井必须建矿井气温预测计算,超温地点必须有制冷降温设计,配齐,降温设施。
A、重建
B、新建
C、改建
D、扩建