As the plunger moves upwards in the barrel
题型:单项选择题
问题:
As the plunger moves upwards in the barrel, injection will commence once the plunger has () the spill ports and the pressure builds up.
A.opened up
B.closed off
C.lined up
D.taken off
As the plunger moves upwards in the barrel, injection will commence once the plunger has () the spill ports and the pressure builds up.
A.opened up
B.closed off
C.lined up
D.taken off