13.An i__________ refers to an organization set up to do a particular type of work, especially research on teaching.

12.It’s our duty to d_______ our country when danger is approaching.

11.We had a party to c_________ mother’s silver wedding.

10.The scientists are on an e___________ to the South Pole for the purpose of watching the great event.

9.They found it to be an a____________ land where the soil was red, bears climbed trees, birds ran but did not fly.

8.We all a ________ him for his bravery in that battle.

7.It is said that at that time people living in mountainous areas didn’t have enough light i________ products.

6.How many new students have been a_________ to our school this year?

5.We found the students very d____________ at losing the race.

4.After I had graduated from college, I continued to d______ myself to research.