The lower section of a piston is called the （）.

[单选题]An aluminum piston has lower inertia and higher coefficient of （） compared to that of cast iron.A . viscosityB . twisting momentsC . inertiaD . thermal expansio

[单选题]The lower end of each piston rod is reduced in diameter to fit a bore in the （）, this being secured to the piston rod by a nut.A . piston gudgeon pinB . piston skirtC . cross-headD . cross-head pi

[单选题](piston area)×(piston stroke)×(numbers of the cylinders)=engine( ).A．brake horsepowerB．displacementC．cylinder volumeD．cylinder clearance

[单选题]lower the gangwayA．调整舷梯B．放舷梯C．收舷梯D．摆动舷梯

[单选题]lower a littleA．升一点儿B．把定C．调整D．降一点儿

[单选题]Section BD．irections: In this section, you will hear 3 short passages. At the end of each passage, you will hear some questions. Both the passage and the questions will be spoken only once. After you hear a question, you must choose the best answer f

[单选题]Section AD．irections: In this section, you will hear 8 short conversations and 2 long conversations. At the end of each conversation, one or more questions will be asked about what was said. Both the conversation and the questions will be spoken only

[主观题]Section AD．irections: In this section, there is a short passage with 5 questions or incomplete statements. Read the passage carefully. Then answer the questions or complete the statements in the fewest possible words.That experiences influence subseq

[主观题]Section AD．irections: In this section, there is a passage with ten blanks. You are required to select one word for each blank from a list of choices given in a word bank following the passage. Read the passage through carefully before making your cho

[主观题]Section CD．irections: In this section, you will hear a passage three times. When the passage is read for the first time, you should listen carefully for its general idea. When the passage is read for the second time, you are required to fill in the b