在下面对话的空格内填上一个适当的词，使对话意思完整，语句正确。

 （A）

A：Mum, I shall not have lunch at home today.

B：Why not, Linda?

A：I want to go to the pet（宠物） shops at noon with my classmates. Most of the students in our class have their own pets. Mum, as you know, I 1    got a pet yet.

B：What 2    of pet do you want to have?

A：A dog 3    a cat. I haven't decided yet.

B：You'd better not keep a dog in our flat. It would make much noise．And a dog has to go out every day, and there isn't a 4    near our building．And the dog food is expensive.

A：Then I'll have a cat．Cats are cheaper than dogs, and they are quiet, too.

B：Yes, cats are easier to5    

（B）

A：Huang Hai, why do you look so tired and worried today?

B：I got up very early this morning as my family has moved to a new building. The new flat（套间） is much 6   than the old one.

A：Congratulations!  You've moved to a new flat!

B：Thanks．But it's about ten kilometres from my new house to the school. It takes me a longer time to go to school. The population of Guangzhou is 7    very fast, you see．But there is not enough space for us to build new buildings in the city centre. Most of the new buildings have to be built in the places 8  away from the city centre.

A：I quite 9  with you．And people spend more money and more time on their way to work.

B：What's more, the traffic will be heavier and the air will be 10   because there are more and more buses and cars. So the population problem may be one of the serious problems of the world today.

（C）

A：Huang Xumei, I'm  glad you can come  for our Thanksgiving（感恩节） dinner.

B：Thanks for  11    me, Helen. Why do you call it dinner when we are eating at noon?

A：Because it's a big  12  . We call it dinner when we have a lot to eat.

B：Is that a chicken? It's so big!

A：No, it's a turkey（火鸡）. It's 13    bigger than a chicken.

B：Why do Americans and Canadians celebrate （庆祝）Thanksgiving?

A：It's  14   your  Mid-autumn Festival.  In China, families get together and enjoy looking at the bright, round 15   In America and Canada, families get together to celebrate the harvest（收获）.

B：So we each have an autumn festival. Something is the same in China, America and Canada．