第二十三课

 twenty-three23

Small change and big efficiency小改变大效率

1．Questions and Speculation问题与猜测

2．The new textbook has been sent to the class. How to send the textbook to all the students quickly?

新课本发到班级了，怎样快速地把课本发给全体同学呢?

3．One by one local hair. 一本一本地发。

4．Or...还可以....

Inquiry and Practice探究与实践

5．Let's test which method is efficient.我们来测试哪种方法效率高。

6．First measure the time used in this method.先来测这种方法用的时间。

7．What practices in life can improve efficiency?生活中哪些做法可以提高效率?

8．I know that … …我知道....

Development and Innovation拓展与创新

9．Design the emergency evacuation drill plan, so that the whole class can safely leave the classroom in the shortest time.

设计应急疏散演练方案,让全班同学在最短的时间内安全离开教室。

10．Don't crowded, pay attention to safety! 不要拥挤,注意安全!