对于要求输送流量较大的离心泵,应采用的离心泵类型是()。
A、双吸式
B、单吸式
C、单级
D、多级
参考答案:A
When the newspaper boy got to a blue door,________,which frightened him away as fast as possible.
A.out a fierce dog rushed
B.out did a fierce dog rush
C.out rushed a fierce dog
D.rushed out a fierce dog
移动性浊音阳性时,腹腔内游离腹腔积液量至少有()
A.300ml
B.120ml
C.500ml
D.1000ml
E.3000ml