汽车从静止开始先做匀加速直线运动，然后做匀速运动．汽车所受阻力恒定，下列汽车功率P与时间t的关系图象中，能描述上述过程的是（   ）

⑴Thank you!____                                  A. It's a circle

⑵How did you come here?____           B. Nice to meet you, too!

⑶Good afternoon!____                        C. I came by bus.

⑷What shape is this?____                    D. Yes, I do.

⑸What's the weather like?____           E. He's a driver.

⑹Nice to meet you!____                     F. Good afternoon!

⑺Do you have a pen?____                  G. I'd like some cakes.

⑻Which one do you want?____         H. You're welcome.

⑼What's he ?____                               I. A short one, please!

⑽Can I help you?____                        J. It's warm.