题目

Washing machines made by China have won ______worldwide attention and Haier has become _____popular name. A. a; the        B./;a    C./;the        D. the; a 答案：B 解析: 考查冠词的基本用法。前空attention为抽象名词，不用冠词，后空意思为变为一个受欢迎的名字可知答案为B。已知Rt△ABC中，∠ACB=90°，AB=5，两直角边AC、BC的长是关于x的方程x2-（m+5）x+6m=0的两个实数根．求m的值及AC、BC的长（BC＞AC）．