Last night, an accident happened at ______crossroads a few meters away from ______school I attend.

A．a; the

B．a; a

C．/; the

D．the; a

指导慢性阻塞性肺疾病患者做腹式呼吸时，吸气与呼气时间之比为( )

A．1.5︰1

B．1︰1.5

C．2︰l

D．1︰2