In the polar regions, the dog mainly_____.

• A、carried supplies

• B、provided companionship

• C、tracked prey

• D、herded caribou(馴鹿)

In the last paragraph, the words “you’re on the same page” mean that 

• A、you’re following the speaker closely

• B、you’re reading the same page as the speaker does

• C、you should know which page the speaker refers to

• D、your story is written on the same page as the speaker’s

57（）