题目

When products made in factories _____, they are thrown away as garbage. A. come to an end    B. are put to use C. are used up       D. wear out 答案：D 解析: wear out本题中意指（become useless form continued use of wear）用坏，穿破，如：The machine will soon wear out.(这机器即将用坏。)come to and end(结束)，put ... to use(投入使用), use up(用完)， come into use(开始投入使用)。如图，已知直线l与坐标轴相交于点A（2，0）、B（0，-3）．（1）求直线l的函数关系式；（2）利用函数图象写出当函数值y＞0时，自变量x的取值范围．