輪機(jī)英語(yǔ)單項(xiàng)選擇題每日一練(2019.08.12)

來(lái)源：考試資料網(wǎng)

1 （）is harmful for fuel pumps, fuel valves, cylinder liner, exhaust valve seats, and the turbocharger blades as well.

2 Most conducting materials such as copper, aluminum, iron, nickel, and tungsten （）.

3 Most hydraulic steering gears are fitted with relief valves which（）

4 The suction - force principle of operation is a typical characteristic of （）.

5 Which of the following statements is correct concerning the “flash point ” of a liquid?（）