如果做托里拆利实验时，不用水银而用酒精，玻璃管至少应该长          m。（ρ=0.8×10³ kg/m³，大气压为1.0×10⁵Pa，g取10 N/kg）

A warm welcome ______ to the American guests at the airport tomorrow morning.

A．is given

B．has been given

C．is going to give

D．will be given