某异步电动机的额定转速n=960转/分，电源频率f=50Hz，则该电动机为（）极。A

阅读理解。

     It was Mother's Day. A man stopped his car at a flower shop to order some flowers. He wanted the

shopkeeper to send the flowers to his mother, who lived two hundred miles away.

     As he got out of his car, he found a young girl sitting on the road crying.

     He asked her what was wrong and she replied, "I want to buy a red rose for my mother, but I only

have seventy-five cents. A rose costs two dollars."

     The man smiled and said, "Come into the shop with me, and I'll buy you a rose."

     He bought the little girl her rose and ordered his own mother's flowers. As they were leaving, he offered

to drive the girl home. She said, "Yes, please! You can take me to my mother." She brought him to a

cemetery (墓地), where she placed the rose on the grave.

     The man was moved. He returned to the flower shop, picked up the flowers he ordered, and drove two

hundred miles to his mother's house.

     Today is the day for your mother. Send a flower to your kind and beautiful mother.

1. After the man bought the girl a rose, they went to _____ together.

A. the cemetery

B. his shop

C. the girl's home

D. his mother's house

2. We can learn from the passage that _____.

A. the girl loved flowers very much

B. the girl loved her mother very much

C. the shopkeeper sent the flowers to the man's mother

D. the man drove to his mother's house to look after her

一个科学研究小组对5000只“冰川豹蛛”进行测量后发现，1996～2005年间，这种蜘蛛的体形平均增大了8%~10%；同期当地每年的解冻期提前了20  -25天。这支持了他们的猜想：剧烈的气候变化对当地蜘蛛的生长产生了影响。该研究小组负责人表示，这种影响的后果很复杂，一下子无法估计出来。这一说法体现了 [ ]

①事物间的联系是客观的、无条件的

②事物本质的暴露和展现有一个过程

③世界总有一些秘密不能为人所理解

④人的认识具有反复性、无限性  

A．①②  

B．③④  

C．①③  

D．②④

我国经济法主体包括( )。

A．国家机关

B．个体工商户、农户及公民

C．企业和其他社会组织

D．企业内部组织和有关人员

一块折射率为、边长为L的正立方体形玻璃砖，被平面CD截去一部分，成为ABCDE五棱柱，如图所示，其中BC=L/2，∠BCD=150°，今有平行光束以45°角入射到AB面上，当它进入玻璃后，如果从玻璃向空气第一次透射出的光线能从DE面射出，试在AB面上确定这种光束的入射范围，并画出典型光线的光路．

1岁小儿，因气管异物窒息入院。治疗中并发脑水肿，遵医嘱使用20%的甘露醇。护士向家长解释使用此药物的作用是（）。

A.迅速降颅压，预防脑疝

B.预防颅内出血

C.预防颅内感染

D.促进脑细胞代谢

E.兴奋呼吸中枢