以下哪个不属于飞机地面勤务？

My father, together with some of his old friends, ___ there already.

—Mum, why do you give me so much popcorn?—_____ the boring time.

HPTACC

HPTACC

HPTACC

HPTACC

CFM56-5B发动机HPTACC使用（）级引气来加热或冷却高压涡轮

当中压级供气时，压力调节是由哪个活门完成？

HMU

HMU