They ______ basketball at six o’clock la

已知集合A={a₁,a₂,a₃,…,a_n},记和a_i+a_j(1≤i<j≤n)中所有不同值的个数为M(A).如当A={1,2,3,4}时,由1+2=3,1+3=4,1+4=2+3=5,2+4=6,3+4=7,得M(A)=5.对于集合B={b₁,b₂,b₃,…,b_n},若实数b₁,b₂,b₃,…,b_n成等差数列,则M(B)=　　　　.

对于一种纯碎公共物品，在其总供给量保持不变的情况下，如果增加一个人对它的消费量，则其他人可消费数量的变化情况是()。

A.相应增加

B.保持不变

C.相应减少

D.趋于平均

阅读理解。

     Tom is a tall boy. He is 178cm tall. He lives in America. On Sunday morning he likes to go to see his

friend. His name is Eric. He is a boy. He has a good garden (花园). There are (有) many trees and roses in

the garden. They are apple trees, orange trees and other (其他的) fruit trees. There are many fruits on the

trees. There are many birds in the garden, too. They are happy. The birds sing in the trees. Tom and Eric

listen to the birds and sing songs with (和┄┄ 一起) them. They draw pictures of birds.

      It's time for lunch. They are hungry. They go to a restaurant. Tom wants some dumplings. Eric would

like a bowl of noodles. After lunch, they go to see movies. They see an action movie. Its name is "Sharp

Shill".

1. Tom _____.

A. has a boy friend

B. is a short boy

C. lives in China

2. Here are many _____ in the garden.

A. flowers

B. cats and dogs

C. fruit trees and flowers

3. _____ sing in the tree.

A. Tom and Eric

B. Birds

C. Fruit

4. Tom and Eric _____.

A. don't like singing

B. don't like birds

C. like birds

5. They _____ after lunch.

A. go to swim

B. play soccer

C. go to movies

D. go home

A．CH₄、C₂H₄

B．CH₄、C₃H₆

C．C₂H₄、C₃H₄

D．C₂H₂、C₃H₆

银行承兑汇票是（）工具。

A.信用衍生 

B.资本市场 

C.利率衍生 

D.货币市场