配电箱要标示（）、（）及（）。
参考答案：负责人；联系电话；责任单位
There are eight _____ people in the tall building, and one _____ of them are children. [ ]
A. thousand, thousands
B. thousand, thousand
C. thousands, thousands
D. thousands, thousand
下图所示模具是什么模具？其工作原理和工作过程是怎样？
