It is ______ the customers’ needs that has made chain stores so popular in big cities in China.
Li Ling was a diligent boy . He ____ go to school though it was raining hard .
— ____ he open the door ? — Yes , please .
— Do you have to take care of your mother at home ? — Yes , I ____ .
— Would you please go to the cinema with me ? — Yes , I ____ .
I''m surprised that he ____ to help me when I needed his help .