But the problem is that it is so easy to “copy and paste” that teachers (5) ________ to change homework assignments or projects every year.

The last U.S. trip to the moon (5) ______ in December 1972.

At 226,000 miles away, the moon is Earth's (4) _______ space neighbour.

“We will return to the moon no later than 2020 and extend the human presence across the (3) _____ system and beyond,” says Michael Griffin, the head of NASA.

Back in 2005, the U.S. space agency announced its plan to send four astronauts to the moon (2) _____ the next 15 years.

 The space agency hopes to (1) _____ humans to the moon again by 2020.

You can be connected to the Internet directly through your own computer or you can hook up to an access system which allows you (5) _________ some of the Internet’s services.

Soon, scientific and educational institutions as well as research departments became (4) _________ in linking up, and, before long, the Internet had expanded into an international information and communication network.