七十

The blues is believed to have originated in the Mississippi Delta, a wedge-shaped region in northern Mississippi between the Mississippi and Yazoo rivers.

据信，蓝调是发源於密西西比州的德尔塔区，这是一个位於密西西比州北部的楔形地区，介於密西西比州及亚祖河之间。

Open your pencil cases. Take out your pencils.

打开你们的文具盒，拿出你们的铅笔。