Each child had a small board and a piece of chalk.

每个孩子都有一块小黑板和一块粉笔。

Ex2: I need a piece of chalk.

我需要一支粉笔。

Someone hit her with a piece of chalk.

有人用粉笔打了她一下。

Describe a circle on the floor with a piece of chalk.

用一支粉笔在地板上画个圈。

It can do all sorts of things a piece of chalk can't do.

它能干一堆粉笔干不了的事

He is drawing something on the blackboard with a piece of chalk.

他正用粉笔在黑板上画东西。

As if it is fair for them to draw with a piece of chalk on the wall.

好像对他们来说用一只粉笔在墙上书写是理所当然的公平。

Then he took a piece of chalk and drew something triangular on the blackboard.

然后他拿起粉笔在黑板上画了一个三角形的物体。

None of the members of his family had ever seen a slate before, or a piece of chalk.

他的家人中没有谁曾经见到过一块石板，或是一枝粉笔。

If you gave him a blackboard and a piece of chalk, he would become a whirlwind of wisdom.

如果你给他一块黑板和一截粉笔，他就会化身为智慧的旋风。