问题
选择题
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
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)。