[ Sentence Completion ]
Professor Stevens had studied many caves, but he had —– before seen the ones in Castleton.
A. never
B. whenever
C. yet
D. every

Random Topics:
Modal AuxiliaryCommunicative GrammarVocabulary and PrepositionsPresent SimplePassive with ModalsQuantifiers, Countable and Uncountable NounsAdverb of MannersGrammar - QuantiflierGerunds and TensesModal AuxiliariesOther quiz:
Modal Verb › ViewPeople who use public parks __________ clean up after themselves.
A. must
B. may
C. ought
D. might
Grammar › View
_____ caterpillars transform into butterflies ?
A. Do
B. Does
C. Was
D. Were