A. If John knows B. Had John known C. If John knew Does John know
A. so frequently B. much more frequently C. more frequent D. far more frequent than
A. a B. an C. / D. the
A. so B. or C. yet D. for
A. need B. must C. should D. can
A. where B. which C. when D. that
A. treated B. were treated C. would treat D. would be treated
A. by B. of C. with D. from
A. on B. through C. all over D. within
A. society B. world C. way D. position