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

<acronym id="kwz2p"><kbd id="kwz2p"></kbd></acronym>

<track id="kwz2p"></track><th id="kwz2p"></th>

<optgroup id="kwz2p"></optgroup>

單項(xiàng)選擇題

Cooling enables the engine metals （） their mechanical properties.

A.to retain
B.to remain
C.to maintenance
D.to have

你可能感興趣的試題

單項(xiàng)選擇題

Constant cooling the various components of diesel engine has a number of functions except for （）.

A.good lubrication
B.low thermal stress
C.good mechanical properties
D.acid corrosion

單項(xiàng)選擇題

Compressed air is used on board ship （）.

A.for starting diesel engines
B.in pneumatic control system
C.in pneumatic tools
D.All the above are true

<track id="3ngaq"></track>

<optgroup id="3ngaq"><i id="3ngaq"><rp id="3ngaq"></rp></i></optgroup>

<optgroup id="3ngaq"><table id="3ngaq"><input id="3ngaq"></input></table></optgroup>

<thead id="3ngaq"></thead>