单项选择题
A.advanced nautical equipment B.advanced performance main engines C.emergency equipment D.communication and language skills
Adjust （） by means of lead wire.A.the clearance of the ...
单项选择题Adjust （） by means of lead wire.
A.the clearance of the main bearing B.the diameter of main bearing C.the gap of main beating D.the tolerance of main bearing
Additives （） protective layers on metal surfaces guardi...
单项选择题Additives （） protective layers on metal surfaces guarding them against corrosion.
A.damage B.form C.dissolve D.contaminate
Acid solution（） in the system can be tested from time t...
单项选择题Acid solution（） in the system can be tested from time to time by putting some on to a piece of lime.
A.strength B.dense C.percentage D.velocity
