For most North American households, lighting ..... 10 percent to 15 percent of the electricity bill. 

A. should                  

B. must                     

C. had                              

D. ought 

A. having no disasters                        

B. likely to have disasters 

C. have very few disasters                 

D. have few disasters 

A. In spite            

B. Although           

C. However                      

D. Despite  

A. skins               

B. roots                        

C. stems                  

D. leaves 

A. and                   

B. but                       

C. So                                

D. or 

A. Certainly 

B. That's OK 

C. Thank you

D. I don't care