随着社会的进步，人类智力成果的作用越来越重要，各个国家通过立法保护公民的智力成果。这样做（    ）

①是为了更有效地鼓励公民的创新精神           ②为公民维护知识产权提供了法律依据

③是为了激励人们创造更多无形财产               ④能有效地杜绝相关侵权行为的发生

____%=4÷5= 24÷____=____：10．

某同学设计了一个用电磁打点计时器验证动量守恒定律的实验：在小车A的前端粘有橡皮泥，推动小车A使之做匀速运动，然后与原来静止在前方的小车B相碰并粘合成一体，继续做匀速运动．他设计的装置如图（a）所示．在小车A后连着纸带，电磁打点计时器所用电源频率为50Hz，长木板下垫着小木片以平衡摩擦力．

根据句意及首字母提示补全对话

A: Hi, Lingling. Could you help me w____ my homework?

B: What is that?

A: Our teacher a____us to write a composition about a famous people. But I have no idea.

B: W____don’t you introduce Confucius?

A: That s____like a good idea. What do you k____about Confucius?

B: Well, Confucius was a great t____and a very wise man. He was a teacher, and he taught lots of students in different countries. And his t____were mainly written in Lunyu. His works are r____by millions of people, and we’re still i____by him nowadays.

A: What are his thoughts?

B: Do you know that parents and grandparents are highly r____ in China?

A: Yes, I do.

B: That’s one of his thoughts.