73. The main engine stops automatically owing to the less lube oil pressure.

A、
A、 The main engine stops manually owing to the less lube oil pressure.
;

B、
B、 The main engine stops automatically owing to the lack of lube oil.
;

C、
C、 The main engine stops automatically because of lower lube oil pressure.
;

D、
D、 The main engine stops manually owing to the less lube oil pressure.