21. Expanding populations and steadily improving communications brought more trade and contact, but also more ________between social groups.
A. cooperation B. friction C. liberation D. distribution
22. —Mike, the results are ______ with our earlier research.
—Fantastic! That’s what we’ve been expecting.
A. apparent B. sustainable C. concrete D. consistent
23. Anyway , we’re here now, so let’s ________some serious work.
A. come up with B. get down to C. do away with D. live up to
24. — Johnson is feeling a bit ______ after last night’s get-together.
— Well, he must have drunk himself stupid during it and he should have a rest.
A. distant B. fragile C. empty D. weird
