Which of the following operations are important to measure the rotation angle of the sugar solution?
A.
Check the bubbles still at the bulge of the tube after sample loading
B.
Direct load the sugar solution tube to the sample container
C.
Adjust the analyzer to get fully-dark view
D.
Shift bubbles in the solution to the bulge of the tube before sample loading
E.
Adjust the handle of eyepiece to get clear view
F.
Record the angle of analyzer before sample loading