[单选题]
A compound microscope has a 1ja 54szz 4tdud fb12b(8-cmr7t f5osy0c7 g9imi gqa+f 86t barrel and an objective with a focal length of 8.0 mm. Wha56ti9fmi a7q0g8ty+cogfs7r t is the focal length of the eyepiece to give a total magnification of 240?
A. $0.13 \; cm$
B. $1.5 \; cm$
C. $1.9 \; cm$
D. $2.3 \; cm$
Post time 2024-1-26 22:03:25