单项选择题 Because of the resulting higher pressures in the cylinder from the combustion of this greater mass of fuel, and the larger diameters, the liner must be made （） at the top to accommodate the higher stresses, and prevent cracking of the material.

单项选择题 Oil is supplied to the crosshead using a swinging arm or a （） and is sometimes boosted in pressure to and efficient lubrication.

单项选择题 Because of the high loads the bearing material is a tin- aluminum alloy bonded to a steel shellThe crosshead pin is highly polished to a （）.