— If you prefer the red evening dress, you’ll have to pay ________ 30 dollars, because it’s made of silk.— Ok. Here you are.

Liu Ying is good at singing. She sings ________ the famous singer.

 –Look! A blind man is in the middle of the street. It’s too dangerous.–Let’s help him go         the street

The math problem is _____ difficult that only _____ students can work it out.

— Eric, did you see my dictionary?— Sorry, Amy. But you can use           . I’m not using it at the moment.