As young adults, it is our_____ to try our best to deal with each challenge in our education with the help of our teacher. 

There are millions of websites on the Internet and there _________ a lot of useful ________ on the websites. 

Linda is thirteen ________ old. She is my friend.

Last month a new kind of electric car was produced in Zhengzhou. Its highest _________ can reach 120 kilometres an hour.

The underlined part in the sentence “I have many good books.” is a/an________.