为帮助大学生学到权威的英语知识，本网站特提供以下资料：
1.First published in 1927, the charts remain an _______ source for researchers.
A intelligent
B indispensable
C inevitable
D identical
2. Please___ dictionaries when you are not sure of____ word spelling or meaning.
A search
B seek
C inquire
D consult
3. It ____ you to at least 50% off the regular price of either frames or lenses when you buy both.
A credits
B entitles
C presents
D tips
4. The __ at the military academy is so rigid that students can hardly bear it.
A confinement
B convention
C discipline
D principle
5. Doctors warned agaisnt chewing tobacco as a _____ for smoking.
A succession
B substitute
C revival
D relief