Into her nineties, her thinking remained______and her character forceful.
查看答案
We have_________ $25 per adult to arrive at a basic room rate
显微镜的分辨率主要取决于:
A. 焦距
B. 数值孔径
C. 放大率
D. 视场角
10 倍望远镜,出瞳口径为 5mm,入瞳口径为:
A. 5mm
B. 10mm
C. 25mm
D. 50mm
数值孔径 NA=0.5 的显微物镜,在空气中工作时的物方孔径角为度,有效放 大率不能超过。