在行动研究中，研究者承担的角色是（）。 A.既是旁观者又是研究者 B.单纯的研究者

阅读理解。

     A young woman was walking through a supermarket to pick up a few things when she noticed an old man following her around. Thinking nothing of it,she ignored him and continued (继续)  shopping. After she got what she wanted, she went to checkout line,but the old man got in front of her,"Pardon me," he said,"I'm sorry if my staring(盯) at you has made you feel uncomfortable. It's just because you look like my granddaughter,who just died recently. And I miss her very much, "

     "I'm very sorry," answered the young woman. "Is there anything I can do for you?"

     " Yes,"  the old man said. " As I'm leaving,can you say ‘Goodbye,Grandpa' to me? It would make me feel so much better. "

     "Sure," answered the young woman.

     As the old man was leaving,she called out, " Byebye,Grandpa ! "

     When she stepped up to the checkout counter(收银台) ,she saw that her total was $ 178.50.

     "How can that be?" she asked. "I only bought a few things ! "

     "Your grandpa said you would pay for him," said the clerk.

1.Why did the old man follow the woman and let her say" Bye-bye,Grandpa" ?     

A. He wanted to steal(偷) her money.

B. She looked like her dead granddaughter.

C. He wanted to stare at her.

D. He wanted her to pay for him.

2. According to the passage we can know that              .    

A. the young woman is a careful person .

B. the young woman is as clever as the old man

C.the young woman was pleased to pay for the old man

D. the young woman didn't know the old man at all

3. What does the word "ignored" mean?

A. 看  

B. 浏览  

C. 忽视  

D. 买

4. How much did it cost what the young woman bought? 

A. $ 178.50.                    

B. Over $ 178.50.

C. $ 78. 50.                    

D. Less than $ 178. 50.

5. Which of the following is the best title of the story?

A. A kind-hearted young woman

B.The total was $178.50

C. Bye-bye,Grandpa

D. An old man and his granddaughter       

计算：(-2)³=（    ） ；(-1)¹⁰= （    ）；-3²=（    ）

属于纯净物的是[ ]

A．粗盐

B．天然气 

C．无水酒精

D．空气

显示非活动性脑猪囊尾蚴最佳的检查方法为（）

A.MRI

B.CT

C.X线平片

D.CT三维成像

E.SPECT

下图（双代号网络计划）的关键路径时间为（）天。

A.13

B.14

C.15

D.11