The accountant has to make a _____ statement of sales revenues every years.
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Please keep what I have told you ____.
A. confident
B. confidential
Increasing the amount of time in your study brings a ____ improvement in your grades.
A. correspondent
B. corresponding
______ films are popular now.
A. Historic
B. Historical
在夫朗和费单缝衍射实验中,用单色光垂直入射缝面,若入射光波长为5000埃,第一级暗条纹对应的衍射角为30°,则缝宽为()
A. 2×10-6m
B. 10-6m
C. 0.5×10-5m
D. 3×10-7m