Speaker A: Excuse me, can you tell me where the Prince's Building is Speaker B:______

A．The Prince's Building Why do you want to go there

B．Sure, if you like, I can show you how to get there.

C．Well, turn to the left at the first corner after the crossroads. It's there near the corner.

D．Strange! What's going on there Three people have asked me how to get there.

如图所示，质量为m的活塞   将一定质量的气体封闭在气缸内，活塞与气缸壁之间无摩擦．a态是气缸放在冰水混合物中气体达到的平衡状态，b态是气 缸从容器中移出后，在室温(27 ℃) 中达到的平衡状态．气体从a态变化到b态的过程中大气压强保持不变，若忽略气体分子之间的势能，下列说法中正确的是  

A．与b态相比，a态的气体分子在单位时间内撞击活塞的个数较多  

B．与a态相比，b态的气体分子在单位时间内对活塞的冲量较大  

C．在相同时间内，a、b两态的气体分子对活塞的冲量相等  

D．从a态到b态，气体的内能增加，外界对气体做功，气体向外界释放了热量