Envelopes（信封） are designed to protect letters.We often see them in our daily life.But do you know when and where the envelope first appeared （出現(xiàn)）？The history of envelopes is probably much longer than you think.
   It is said that the envelope first appeared in ancient China.People used it to protect royal messages.However，the early envelope was nothing like what we use today.It was made from clay（黏土） and looked like a ball.After the message was put into it，the envelope would be scaled（封絨） with more clay.To read the message，people had to break the "envelope".
   The first paper envelope appeared around 200 B.C.The Chinese invented（發(fā)明） it.However at first，people used it only to send money to each other as gifts.Later people used it for sending messages.The design of the early paper envelope was very simple.It was just a piece of paper folded and sealed with wax.The envelope was made completely by hand，so it was very expensive.
   In the 19th century，printing and manufacturing methods improved greatly In 1853，the American inventor Russel Hawes invented an envelope maker.The machine could produce about 12，500 envelopes every day.Because of this，the cost of envelopes went down.
   Today，e-mails have become more popular than handwritten letters.However，billions of envelopes are used around the world every year.They are still part of modern life.
（1）Where did the envelope first appear？

In ancient China.

In ancient China.

（2）What did the envelope look like at first？

A ball.

A ball.

（3）What did people use the paper envelope for at first？

People used it only to send money to each other as gifts.

People used it only to send money to each other as gifts.

（4）How many envelopes could a machine produce every day in 1853？

About 12，500.

About 12，500.

（5）What do you think of the use of envelopes in our life now？

They are still part of modern life.

They are still part of modern life.