问题 实验题

(6分)不知你有没有意识到,我们的生活和学习都离不开神经系统的调节。下面,就让我们通过“绿叶在光下制造有机物”这节实验课上的经历来感受一下吧。

(1)课的一开始,老师要交待实验要求。听清老师讲话,依赖于你的听觉。在听觉形成过程中,能够直接接受外界声波冲击产生振动的结构是________;具有对声波敏感的细胞,能够接受振动刺激形成神经冲动的结构是 __________。

(2)进行实验之前,需要对照老师板书的材料用具清单清点实验台上的物品。你不仅可以看清近处的材料用具,也能看清远处的板书,这是因为眼睛结构中的________具有调节作用,使外界物体形成的物像能够落在视网膜上。

(3)实验过程中,如果你在点燃酒精灯时,手不小心碰到了火焰,会迅速缩回来,然后才感觉到灼痛。这是因为,完成缩手反射的神经中枢在 __________中,而痛觉的形成是在_________。

(4)当发现酒精里的叶片变成黄白色时,你可以准确地用镊子夹起小烧杯,放在实验台上。你的上述动作之所以能够协调准确,是因为有神经系统中     的调节作用。

答案

(1)鼓膜 耳蜗    (2)晶状体(3)脊髓 大脑皮层    (4)小脑

声波传到中耳,会引起鼓膜的振动,耳蜗上有听觉感受器,能感受刺激形成与听觉有关的神经冲动,晶状体具有调节作用,所以人能看清远近不同的物体,缩手反射属于非条件反射,神经中枢位于脊髓灰质,痛觉是感觉,人体的感觉中枢在大脑皮质,小脑具有协调全身肌肉活动,维持身体平衡的功能。

单项选择题
阅读理解

D

A husband-and-wife team from California reached the Pacific Ocean after a 4,900- mile-cross

-country walk, becoming the first to backpack the American Discovery Trail in one continuous

walk. 

Marcia and Ken powers, of Pleasanton, started the travel across 13 states, through 14 national parks and 16 national forests on Feb. 27 from Cape Henlopen in Delaware. Nearly eight months later, the excited couple walked through water into the Pacific Ocean at Point Reyes, a day ahead of time. 

“We are a little sad that a great adventure is over. It was a fantastic adventure. And now we go home and just do housework. It's really sad.” Marcia, who said she's in her 50s, and her 60-year-old husband traversed cities, desert, mountains and farmland before reaching the Pacifics alone with arms around each other' s backpacks.

They overcame deep snow in the East, a quicksand in Utah, close lightning strikes in the Mid- west and strong desert sandstorms in the West while averaging 22 miles a day and taking only four days off. But they enjoyed the French history of St. Louis' the beauty of the Colorado Rockies and the kindness of strangers they met along the way. They particularly remember two brothers ---- a

doctor and dentist-------who put them up in their homes, after terrible days, and a motorcyclist who gave them water after they failed to find any on Utah's lonely Wah Wah Desert.

“Americans are truly warm-hearted and wonderful people.” Marcia Powers said. “We got to meet people that we would never meet in our daily living at home. We got to touch it with our feet and hands and smell all its scents and hear its wildlife. It' s an amazing country,” she added.

68. Which of the following about couple's walk is TRUE?

A. The walk covered more than 13 states.

B. The walk lasted about half a year.

C. The walk didn't meet any desert.

D. The walk might end before October 27.

69. The underlined word “traversed” in the third paragraph means “____________.”

A. enjoy                       B. move across, through or over

C. overcome                    D. look at

70. According to the text, we can infer that during the walk the couple __________.

A. were treated warm-heartedly by the local people

B. never stopped to have a rest

C. were ever caught in a heavy rain and became ill

D. felt the quicksand in Utah was very interesting

71. The couple went through many places except ____________.

A. big rivers       B. desert      C. hills       D. fields