黑板

hēi bǎn shang yǒu yī zé tōng zhī

黑板上有一则通知。

A notice is written up on the blackboard.

kàn hēi bǎn bù yào kàn chuāng wài

看黑板，不要看窗外。

Look at the blackboard. Don't look out of the window.

qǐng dà jiā kàn hēi bǎn

请大家看黑板。

Please look at the blackboard.