Excessively worn, or polished ends on a diesel engine valve spring, indicate（） ["burned exhaust valves","excessive spring compression","spring surge","worn valve seat"]
打印机不能打印大多由于打印机使用、安装、（）不当造成的。 ["软盘","设置","习惯","打印"]
在编辑WORD文档时，若要在当前产生新的一行，但不是产生新的段落，新行的格式与当前段落格式相同（即插入人工分行符）。满足此要求的操作是按下（）键。 ["ENTER","ALT+ENTER","CTRL+ENTER","SHIFT+ENTER"]
A loud clicking noise from the valve compartment of an operating diesel engine would indicate（） ["worn valve seats","worn main bearing","excessive valve clearance","weak rocker arm spring"]
计算机病毒会被复制特性称为（）。 ["变异性","分裂性","传染性","分析性"]
气缸严禁使用（）。
