搜题请搜索小程序“爱下问搜题”
问题 不定项选择

如图所示的皮带传动装置中，O为轮子A和B的共同转轴，O′为轮子C的转轴，A、B、C分别是三个轮子边缘上的质点，且RA＝RC＝2RB，则三质点的向心加速度大小之比aA∶aB∶aC等于

[ ]

A．4∶2∶1 　　　　　　　　　　　

B．2∶1∶2

C．1∶2∶4 　　　　　　　　　　　

D．4∶1∶4

答案

答案：A

写句子

　　晚会中，有一位同学“雅兴大发”，连吟出了几句句式整齐一致的“雅句”。请你顺着“雅”的思路，续上一句。

　　初中三年，光阴荏苒。忆同学少年，良多趣味。我们曾吟周敦颐《爱莲说》，立下君子之志；我们曾学毛 * * 指点江山，歌颂风流人物；________，________……如今，这些都如片片枫叶，珍藏在你我青春的诗集。
查看答案
补全对话，情景问答

从Ⅱ栏中找出与Ⅰ栏相对应的答语。

                            Ⅰ                                          Ⅱ

( ) 1. Hello! What's your name?                  A. It's a violin.

( ) 2. Why do you like math?                      B. It's ten dollars.

( ) 3. How is your aunt?                              C. It's Monday.

( ) 4. What club do you want to join?          D. Yes, I do.

( ) 5. Do you want to go to a movie?           E. She is fine, thank you.

( ) 6. How much is the shirt?                       F. I want to join the music club.

( ) 7. Is this your pencil?                             G. My name is Cindy Smith.

( ) 8. Are you Mrs Miller?                          H. Because it's interesting.

( ) 9. What's this in English?                        I. Yes, it is.

( ) 10. What day is it today?                       J. Yes, I am.
查看答案