第6题: [单项选择]Engine operating conditions may be indicated by the color of the exhaust smoke.Black smoke could indicate() A. an insufficient speed droop setting B. an overloaded engine C. clogged drain holes in the oil control rings D. complete combustion 参考答案:B
第33题: [单项选择]三条或三条以上的发育沟相交所形成的凹陷称为() A. 窝 B. 点隙 C. 外展隙 D. 楔状隙 E. 邻间隙 参考答案:B 答案解析:考点:概念区别。选项A窝是指牙冠舌面及合面上不规则的凹陷;选项B点隙是指3条或3条以上发育沟的汇合处所构成的点状凹陷;选项C和D是相同的概念在正常接触区的周围均有呈V字形的空隙称为楔状隙或外展隙。选项