Between the______ (空气进气口) and APU firewall is approximately nin

Between the______ (空气进气口) and APU firewall is approximately nine feet of air inlet ducting leading into the _____(集气室).

A.air inlet door，air inlet plenum

B.air port, air plenum

C.air control unit,air inlet plenum

D.air inlet door，guide vane

正确答案是A