It is said that tea can improve creative power of the literary （文学的） artists in ancient China.According to Lu Yu's Tea Classics，tea-drinking in China can be traced back （追溯） to the Zhou Dynasty - tea was discovered by Shen Nong and became popular as a drink in the State of Lu because of Zhou Gong.

   Tea-drinking in China has a history of four thousand years.As the legend （传说） has it，Shen Nong tasted hundreds of wild plants to see which were poisonous，in order to prevent people from eating the poisonous plants.It is said that he was once poisoned but was saved by eating some leaves of an evergreen plant with white flowers.Later，people called the leaves that saved his life "cha".

   In modern times，people still keep tea-drinking as one of their daily activities.According to the study，tea can also have effects on some modern illnesses.To those who have to work with computers for a long time，drinking tea can help them to build up a wall against the computer radiation.To those who may have too much fat，drinking tea can help them to recreate a new balance in their bodies.And to those aged people，drinking tea is also a good way to keep a calm mood for a longer life.

（1）Tea-drinking in China can be traced back to 　    　.

A．	the Zhou Dynasty
B．	the Xia Dynasty
C．	the Qing Dynasty
D．	the Tang Dynasty

（2）The underlined word "poisonous" in the passage means" 　    　"in Chinese.

A．	供饮用的
B．	美味的
C．	多姿多彩的
D．	有毒的

（3）What does Paragraph 3 mainly tell us？ 　    　

A．	Shen Nong was once poisoned.
B．	Shen Nong was a hero.
C．	The birth of tea.
D．	Tea became popular.

（4）What is the main idea of this passage？ 　    　

A．	The legend of Shen Nong.
B．	The history of tea-drinking in China.
C．	Drinking tea can help people live longer.
D．	Tea can have effects on some modern illnesses.