As applied to staff readings, the correc¬tions for curvature and refraction are respectivelyThe above table shows a part of a level field book. The value of X should be

As applied to staff readings, the correc¬tions for curvature and refr

1.	As applied to staff readings, the correc¬tions for curvature and refraction are respectivelyThe above table shows a part of a level field book. The value of X should be
A.	100
B.	98.7
C.	103.3
D.	102.3
Answer» B. 98.7