1. acute A. alike B. bag C. back D. pack 2. war A. charm B. arch C. dwarf D. cigar 3. drop A. echo B. code C. close D. mop 4. thus A. thumb B. there C. think D. throw 5. image A. target B. plug C. organ D. imagine 答案:ACDBD设U=R,A={x|mx2+8mx+21>0},CUA=,则m的取值范围是( )A.0≤m< B.m>或m=0C.m≤0 D.m≤0或m>