Speaker A: 911 Emergency.Speaker B:______

A．We need your help. Someone has broken into our house.

B．All fight. Hurry up, I' m in hospital.

C．How much is the phone call

D．May I speak to Dr. Wang, please

下列供热方式最有利于环境保护的是[    ]

A．用煤做燃料供热

B．用石油做燃料供热

C．用天然气或煤气做燃料供热

D．用太阳能灶供热