近年来，原油价格持续上涨。为降低对石油的依赖程度，我国乙醇汽油的使用在不断增加，目前，我国已经成为世界第三大生物燃料乙醇生产国。高油价推动乙醇燃料的生产与使用表明

①价格变动可以调节生产，对生产经营有重要影响

②一种商品价格上升，会增加该商品的供应量

③一种商品价格上升，会使这种商品的替代品的需求量增加

④一种商品价格上升，会使这种商品的互补商品的需求量增加

A．①②

B．②③

C．③④

D．①③

情景交际。

A. She has got a fever

B. Will you go wilh us?

C. Isn't she feeling well?

D. Are you coming later?  

E. What do you have to do?

F. Don't get stressed out. You should have a good rest.  

A: We are going to see a film.1._____

B: I'm sorry. I can't.                                                            

A: 2._____                                                        

B: I have to see Lucy in the hospital.                                              

A: What's wrong with her? 3.______                                         

B: 4.______                                                                

A: I'm sorry to hear that. 5.______                                      

B: I'm afraid I can't.