小学新标准英语三年级起点5B 20

[00:00.00] Unit¹ two
[00:04.05]What do you have to do?
[00:05.69]1.Look,listen and write the numbers of the pictures.
[00:16.56]How do you send an E-card?
[00:19.83]What do you have to do?
 

1 unit   

n.单位，单元，部件，元件，装置

参考例句：

• This unit is very hard.这个单元很难。
• This textbook has twenty units.这本课本有二十单元。