One day, a little boy comes into a shop and says to the shop assistant, “I want to buy twelve exercise books of 6 cents(美分)each and nine pencils of 10 cents each. How much is that altogether(总共)? ”

The shop assistant writes these numbers down on a piece of paper and thinks for a minute. Then she says, “1 dollar 62 cents. ”“If I give you ten dollars, how much money will I get back? ”“You will get 8 dollars 38 cents for change. Here you are. These are the things you want. ”
“No, thank you. I don’t want to buy anything. ”The boy looks at the piece of paper and says politely, “This is my math homework. Thank you very much. Can I take it away? ”
The story happens______.

A．in a shop

B．at a mall

C．in a supermarket

D．at school

The little boy comes to the shop for______.

A．nine pencils

B．some books

C．nothing

D．his homework

The little boy is______.

A．bad

B．naughty but clever

C．stupid(愚蠢的)

D．hard-working

At last the shop assistant must be______.

A．excited

B．happy

C．angry

D．surprised

The underlined word “change” in the second paragraph means______.

A．零钱

B．交换

C．改变

D．金钱