99色精品-9色在线-99色在线-99色视频国产欧美日产一区二区三区_亚洲精品亚洲人成在线观看_四虎在线精品永久观看_免费一级a一片久久精

<pre id="wmzul"><optgroup id="wmzul"><strong id="wmzul"></strong></optgroup></pre>

<pre id="wmzul"><legend id="wmzul"></legend></pre>

<dd id="wmzul"></dd>

<em id="wmzul"></em>

單項選擇題

Each cylinder has one starting valve which is usually opened by air pressure and closed by （）

A.nuts and bolts
B.new joints
C.spring force
D.sealing rings

你可能感興趣的試題

單項選擇題

Each crank is made up of two crank webs joined by a common（） to which the bottom endbearing is fitted.

A.throw
B.crankshaft
C.crankpin
D.crosshead

單項選擇題

During working, when the piston is near the （）, the air ignites the fine spray of fuel.

A.TDC
B.DTC
C.BDC
D.BCD

<pre id="i5vou"><legend id="i5vou"><div id="i5vou"></div></legend></pre>

<pre id="i5vou"></pre>

<pre id="i5vou"><strong id="i5vou"></strong></pre>