单选题
1分
Exhaust valve grooving and corrosion is caused by certain components of residual fuel oil. These com...
Exhaust valve grooving and corrosion is caused by certain components of residual fuel oil. These components are sodium, sulfur, and ______.
参考答案: A
参考解析: 注:渣油中的某些成分会引起排气阀划痕和腐蚀。这些成分是钠、硫和钒。