题目

 We all know the weather in the south is much warmer than __________ in the north.  A. it           B. that           C. what            D. one 答案：B已知大于1的正数x，y，z满足x+y+z=33．（1）求证：x2x+2y+3z+y2y+2z+3x+z2z+2x+3y≥32．（2）求1log3x+log3y+1log3y+log3z+1log3z+log3x的最小值．