【单选题】Which lubricating oil additive is used in diesel engines to reduce the tendency for sludge and varnish to form. on the engine parts?
【单选题】已知液化石油气气相的各组分质量成分为 在标准状态下的平均动力黏度为( )[各组分的动力黏度(10-6Pa.S)为:C3H8=7.65, C4H10=6.97]
【单选题】已知空气的密度ρ为1.205kg/m3,动力黏度(动力黏滞系数)μ为1.83×10-5Pa·s,那么它的运动黏度(运动黏滞系数)υ为( )。
【单选题】Sea water is not directly used as a coolant for engines because of its _____.
【单选题】已知空气的密度ρ为1.205kg/m 3 ,动力黏度(动力黏度系数)μ为1.83×10 - 5 Pa·s,那么它的运动黏度ν为( )。
【单选题】[2005年,第77题]已知空气的密度P为1.205kg/m 3 ,动力黏度(动力黏度系数)μ为1.8310 -5 Pa.s,那么它的运动黏度(运动黏滞系数)v为( )。
A.
2.2×10\r\n -5 \r\ns/m2
B.
2.2×10\r\n -5 \r\nm\r\n 2 \r\n/s
C.
15.2×10\r\n -6 \r\ns/m\r\n 2
D.
15.2×10\r\n -6 \r\nm\r\n 2 \r\n/s
【简答题】Unit 3 (Reading A) Match the business meals with their characteristics.A. breakfast meetingsB. breakfast meetingsC. lunchD. lunchE. afternoon tea or coffeeF. afternoon tea or coffeeG. dinnerH. dinner