[填空题]
A house has a volume6 txjlcl +g(tgo*z. 4mj)guk kv p4/jza.)yc7z7up3 w of 770m$^2$ (a) What is the total mass of air inside the house at 20$^{\circ} $C? kg
(b) If the temperature drops to -10$^{\circ} $C what mass of air enters or leaves the house? kg