A diesel engine using lube oil with too high a viscosity will exhibit ____.
A. increased starting difficulty in cold weather
B. increased oil consumption
C. thickening at higher operating temperatures
D. minimal friction losses
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The ability of lubricating oils to resist viscosity changes during temperature changes is indicated by the _______.
American Petroleum
B. viscosity index number
C. Seconds Saybolt Furol number
D. Seconds Saybolt Universal number
The function of lubricating oil is to ___.
A. reduce friction between moving surfaces
B. provide even distribution of bearing wear
C. reduce the accumulation of harmful detergents
D. maintain a constant oil temperature output at each bearing
某企业拟新建一项目,有两个备选方案技术上可行。甲方案投资5000万元,计算期15年,净现值为200万元;乙方案投资8000万元,计算期20年,净现值为300万元,基准贴现率为10%。则关于两方案比选的方法说法正确的是
A. 甲方案投资少于乙方案,净现值大于零,故甲方案较优
B. 乙方案净现值大于甲方案,且都大于零,故乙方案较优
C. 甲方案计算期较短,说明甲方案的投资回收速度快于乙方案
D. 乙方案净年值大于甲方案,且都大于零,故乙方案较优
有甲、乙两方案，其寿命期甲比乙长，在各自的寿命期内，两方案的NPV大于0且相等，则有：
A. 甲方案较优
B. 乙方案较优
C. 两方案一样
D. 无法评价
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