问题 实验题

下图模拟的是呼吸时膈肌的运动情况,请根据图回答下列问题:

⑴图中气球代表的是      ,瓶底的橡皮膜代表的是____________。

⑵如图乙所示,用手下拉橡皮膜时气球会胀大,这表示_________气的过程。在人体内,此过程进行时,橡皮膜代表的结构会_______(填“收缩”或“舒张”),其顶部下降,胸廓的上下径增大,使得胸腔容积_______(填“增大”或“缩小”),肺便扩张,胸腔内的气体压力相应_______(填“增大”或“减小”)。

答案

⑴肺   膈/膈肌  ⑵吸 收缩 增大 减小

题目分析:呼吸肌的收缩和舒张而造成胸廓有规律的扩大与缩小,叫呼吸运动,包括吸气和呼气两个过程。呼吸肌主要是肋间肌和膈肌。膈肌的收缩和舒张使胸廓的上下径变化。A图表示呼气过程,B图表示吸气过程。

(1)图中气球代表的是肺,瓶底的橡皮膜代表的是膈肌。

(2)吸气时:肋骨间的肌肉和膈肌肌收缩→肋骨向上向外移动(膈肌顶部下降)→胸廓扩大、胸廓容积增大→肺随着扩张→肺内气压小于外界大气压力→气体入肺,(呼气时:肋骨间的肌肉、膈肌舒张→肋骨下降,膈肌顶部回升→胸廓容积缩小→肺借弹性回缩→导致肺内气压大于外界气压→气体出肺)故如图乙所示,用手下拉橡皮膜时气球会胀大,这表示吸气的过程.在人体内,此过程进行时,橡皮膜代表的结构会收缩,其顶部下降,胸廓的上下径增大,使得胸腔容积扩大,肺便扩张,肺内的气体压力相应减小,于是气体就被吸入。

阅读理解

Robots are smart. With their computer brains, they help people work in dangerous places or do difficult jobs. Some robots do regular jobs. Bobby, the robot mail carrier, brings mail to a large office building in Washington, D.C. He is one of 250 robot mail carriers in the United States. Mr. Leachim, who weights two hundred pounds and is six feet tall, has some advantages as a teacher. One is that he does not forget details. He knows each child’s name, their parents’ names, and what each child knows and needs to know. In addition, he knows each child’s pets and hobbies. Mr. Leachim does not make mistakes. Each child goes and tells him his or her name, then dials an identification (识别) number. His computer brain puts the child’s voice and number together. He identifies the child with no mistakes.

Another advantage is that Mr. Leachim is flexible. If the children need more time to do their lessons they can move switches. In this way they can repeat Mr. Leachim’s lesson over and over again. When the children do a good job, he tells them something interesting about their hobbies. At the end of the lesson the children switch Mr. Leachim off.

小题1:The first paragraph of the passage tells us

A.human beings are not as smart as robots

B.robots will take the place of man to rule the earth

C.we can only use robots to do some regular jobs

D.robots can help people in many different ways小题2:What is the most important thing Mr. Leachim can do in his lessons?

A.To meet the needs of each student.

B.To talk to the students in different languages.

C.To keep everyone’s interest in his lessons.

D.To introduce more hobbies to the children.小题3:The underlined word “flexible” probably means

A.not strict

B.not hard

C.suitable

D.changeable小题4:Which of the following statements may be TRUE according to the passage?

A. There are 250 robot teachers in the United States.

B. Mr. Leachim is run and controlled by electricity.

C. Bobby works in a large office building in Washington D.C.

D. The lessons taught by Mr. Leachim are given on a TV set.

单项选择题