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

單項(xiàng)選擇題

Oil oxidation, as a result of excessively high lube oil temperature, is harmful to a diesel engine because ()

A.oil foaming will occur
B.large quantities of oil are consumed
C.lube oil viscosity is always decreased
D.corrosive by-products are usually formed

微信掃碼免費(fèi)搜題