观察图所示实验，回答以下问题：（1）实验现象：当活塞迅速下压时，棉花会____

发布时间：2017-07-26 16:25 │ 来源：www.tikuol.com

题型：问答题

问题：

观察图所示实验，回答以下问题：

（1）实验现象：当活塞迅速下压时，棉花会______．

（2）现象分析：因为活塞对空气______，使空气的______增加，______升高，达到棉花的着火点，从而使棉花燃烧起来．

（3）实验结论：______．

考点：物体内能的改变方法（做功、热传递）

题型：问答题

完形填空。

     There was a woman in Detroit ,who had two sons.  She was worried about them, especially the younger one, Ben, because he was not doing well in school.  Boys in his class made jokes about him because he seemed so __1_   .
     The mother    _2_   that she herself would have to get her sons to do better in school.  She told them to
go to the Detroit Public Library to read a book a week and do a book report for her.
    One day, in Ben's   _3   , the teacher held up a rock and asked if anyone knew it. Ben put up his hand
and the teacher let him   _4_  . "Why did Ben put up his hand?" His classmates wondered. "He _5_   said
anything. What could he possibly want to say?
     Well, Ben not only   _6   the rock, but also said a lot about it.  He named other rocks in its group and
even knew   _7   the teacher had found it. The teacher and the students were   _8_  . Ben had learned all
this from doing one of his book   _9_   .
     Ben later went on to the    _10   of his class. When he finished high school, he went to Yale University
and at last became one of the best doctors in the United States.

( )1. A. clever
( )2. A. seemed
( )3. A. class
( )4. A. think
( )5. A. always
( )6. A. found
( )7. A. whether
( )8. A. afraid
( )9. A. pictures
( )10. A. top

B. hard
B. decided
B. room
B. leave
B. ever
B. played
B. what
B. surprised
B. exercises
B. end

C. slow
C. wondered
C. office
C. ask
C. quickly
C. knew
C. where
C. worried
C. shops
C. back

D. quick
D. told
D. lab
D. answer
D. never
D. heard
D. why
D. unhappy
D. reports
D. front

查看答案

题型：问答题

--There are forty-eight students in our class.

--___________.

A．You’re welcome

B．You’re all right

C．You’re right

D．Excuse me

查看答案

题型：问答题

麻疹前驱期最有诊断价值的表现是（）。

A.皮肤红色斑丘疹

B.上呼吸道卡他症状

C.口腔麻疹黏膜斑

D.结膜炎

E.高热

查看答案

题型：问答题

气候干燥、光照充足、昼夜温差大,使番茄具有较高的色素和可溶性固形物含量。从20世纪90年代起,我国某地开始大规模种植、加工番茄,生产能力占到全国近90%,是世界上最适宜种植番茄的区域。据此回答下列各题

小题1:该地最可能为我国的(　　)

A．福建

B．新疆

C．黑龙江

D．安徽小题2:番茄加工产业已成为该地重要的外向型产业,为进一步提高产品在国际市场上的竞争力,应该(　　)

①抓好对外宣传,以拓展市场　 ②扩大外延,增加种植面积 ③抓好龙头企业建设,以带动品牌　④抓好科技投入,不断提高质量　⑤加大原料出口能力,增加收益

A．①②③

B．①④⑤

C．②③④

D．①③④

查看答案

题型：问答题

中 * * 办公厅首任秘书长是（）

A.李富春

B.任弼时

C.刘 * *

D.朱德

查看答案

更多题库