单项选择题
A.point of opening B.speed of opening C.lift from its seat D.all of the above
Which of the listed devices could be used as a ring gro...
单项选择题Which of the listed devices could be used as a ring groove tool during preparation for the installation of new rings?（）
A.Steel brush B.Fine emery cloth or steel wool C.A section of the removed compression ring D.A case hardened scraper
The main source of fuel injection system malfunctions i...
单项选择题The main source of fuel injection system malfunctions is （）
A.improper adjustments B.contaminated fuel C.coated fuel lines D.excessive vibration
The most crucial time for any bearing with regards to l...
单项选择题The most crucial time for any bearing with regards to lubrication is （）
A.during low loads B.after proper oil viscosity is reached C.during starting D.after cleaning filters
