质量为2×10³kg的汽车，保持40kW的功率行驶，能达到的最大速度为20m/s．当它以最大速度前进时，所受阻力的大小为____ N，若汽车受阻力大小不变，它的速度为10m/s时加速度的大小为____ m/s²．

根据短文，判断正误。

   My name is Ted Pike. I am a worker in a big store. I don't work in the morning. I only work at night. Every morning I come home at about half past six. I have breakfast at seven. After breakfast I go to bed. I get up at about half past two. I have lunch at a quarter to three and supper at twenty to eight. Then I go to work at a quarter past eight. I start work at nine. I look after the store every night. I like my work very much.

① How much cheese do you want ?   ____              A. They will come tomorrow.

② How many things are there ?  ____                      B. I'm shopping .

③ When will these things come ? ____                    C. Half a kilo.

④What are you doing ?  ____                                   D. Thirty-seven.