阅读理解。

                                                                  Let's Visit the Zoo!

     Come and see the Indian elephants and the new tigers from America. The bears are waiting to meet

 you, and the monkeys from China are waiting to throw things to you. The lovely dogs from Australia are

  waiting to laugh at (嘲笑) you, and the giraffes from Zambia are waiting to look down on you. 

       Tickets

     Adults: ＄2.00

     Children:over 12: ＄1.00    under 12: Free

     Opening time

     9:00 a.m.～4:00 p.m. (but 10:00 a.m.～3:00 p.m. on Friday.)

     Keep the zoo clean! Do not touch, give food or go near the animals.

1. How many kinds of animals are talked about in the passage?

    A. Four.        

    B. Five.        

    C. Six.        

    D. Seven.

2. Now Mr Smith is in the zoo with his two sons, one aged 14 and the other aged 6.

     How much are the tickets together?

    A. ＄4.00      

    B. ＄2.00      

    C. ＄3.00      

    D. ＄1.00

3. Which of the following is the visiting time?

    A. 8:30 a.m. Monday.  

    B. 9:30 a.m. Friday.

    C. 3:30 p.m. Sunday.  

    D. 5:30 p.m. Tuesday.

丙烯用量最大的是生产（）。

A.聚乙烯

B.聚丙烯

C.乙烯