— I'm sorry. I lost the key to your bike.

—________. I have another one.

A．You’re welcome

B．Oh, really

C．It doesn't matter

D．That’s all right

如图所示是质量相等的两部分同种气体的等压线，根据图中给出的条件，当t=273℃时，气体A的体积与气体B的体积V_A：V_B=______，它们的压强之比P_A：P_B=______．