After a whole day’s heavy work ,the old worker returned home ,______________________.

A．hungry and tiring

B．hunger and tired

C．hungry and tired

D．hunger and tiring

吸式焊炬在点火时应先开氧气阀门，再开乙炔气阀门，然后（），调整火焰。熄火时应先关闭乙炔气阀门，再关闭氧气阀门。