The ports are drilled in the liners at an angle of approx 20℃ the result being that （） is given a rotary movement.

[单选题]Passages are drilled in the crankshafts of diesel engines to provide lubricating oil to the （）.A . main bearingsB . connecting rod bearingsC . piston pin bushingsD . All of the above

[单选题]The cylinder liners are made of _____ and the cylinder surfaces are sometimes chromium-plated.A．steelB．copperC．cast ironD．stainless steel

[单选题]The withdrawing of the cylinder liners, in general, depends on their （）.This may amount to approximately 1/120 of the diameter in some engines.A . correct maneuveringB . wearC . working efficiencyD . maintenance

[单选题]A number of cylinder liners are enclosed in one cast iron casing to form a （）.A . cylinder coverB . cylinder blockC . cylinder frameD . bed-plate

[单选题]The cylinder liners are made of （） and the cylinder surfaces are sometimes chromium-plated.A . steelB . copperC . cast ironD . stainless steel

[单选题]The cylinder covers and the liners are bolted together by means of （）.A . bolts welded into the cylinder headB . bolts welded into the cylinder framesC . studs screwed into the cylinder headD . studs screwed into the cylinder frame

[单选题]The scavenging air ports are located at （） that they are just exposed by the upper edge of the piston when the piston is in the bottom dead center position.A . so a heightB . such a heightC . so highD . such high

[单选题]The author mentions the ports of Los Angeles and Long Beach to ______.［A］prove they are the largest ports in the United States［B］demonstrate they create many new job opportunities［C］highlight that shipping is less glamorous than making movies［D］empha

[多选题] 有关Ports正确的是（）A . 是套接字的一部分B . 可以设置的范围为1～1024C . HTTP服务的端口号为80D . 是协议设置好的，不能认为改动

[单选题]As the plunger moves up, the ports are closed and the fuel （） and delivered to the injector nozzle at very high pressure.A . being compressedB . to be pumped upC . is pressurizedD . are built u