Worn out ring grooves should be （） to standard dimension after being welded.

[单选题]The piston ring grooves for a standard engine are （）A . chromium-plate against wearB . anti-corrosion treatedC . white metal lined against wearD . flame hardened against wear

[单选题]The piston rings if found worn out （） and supplied by shipchandler.A . must replaceB . must to be equippedC . has to be repairedD . have to be renewed

[主观题]I had worn out two pairs of boots on the walking tour , I needed a third one (疑问：此处的a third 能不能换成the third ）谢谢

[单选题]Max: You should go out more.Peter: (58) ?

[单选题]In order to ______ the disease, the first thing we should do is to do resea

[单选题]These piston rings are so badly worn that they must be （）.A . renewedB . weldedC . machinedD . chromium-plated

[单选题]The lowest ring of a piston is （）.A . a coil springB . a sealing ringC . an oil distributor ringD . main seal ring

[名词解释] 神经环（nerve ring）

[名词解释] Ring topology环拓扑

[单选题]A single piece（） fitted with bronze rings guides the piston in the cylinder liner.A . piston skirtB . piston crownC . guide wayD . cross-head