题目

Out of the crowded bus      , who was dressed in a black suit and waved to a woman. A. a tall man in his thirties stepped       B. stepped a tall man in his thirties C. did a tall man in his thirties step      D. did a tall man step in his thirties 答案：B 解析: 略下列各式中，是一元一次不等式的是（  ） A.5+4＞8　　B.2x－1　　C.2x≤5　　D.－3x≥0