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 against chewing tobacco as a _____ for smoking.
A succession B substitute C revival D relief
（做完后才能看答案哦！）