Sky lanterns

According to Chinese history, sky lanterns were first used by Zhuge Kongming. He sent them out to sky for help when in trouble. Today, sky lanterns are used at festivals and other celebrations. They're made of bamboo and covered with paper. When does the lanterns are lit, they slowly rise into the air like small hot-air balloons for all to see. They are seen as bright symbols of happiness and good wishes.

Good writing! Remember to put a space after punctuations, not before. Example:
<em>Sky lanterns are beautiful.I like them. << </em>not correct<em>
Sky lanterns are beautiful. I like them. <<</em> correct