单项选择题
Measure （） by means of lead wire.
A.the clearance of the main bearing B.the diameter of main bearing C.the hardness of main bearing D.the tolerance of main bearing
单项选择题 Measure （） by means of lead wire.
单项选择题 Marine four-stroke diesel engines are mainly （）.
单项选择题 Main bearings are required to support the crankshaft at each （）.
