This is a story from a meeting held by some people and two things in nature. We call it the Four-Sided Talk. Let’s “listen to” everyone carefully and find out what they think.

People: We have lived on the earth since ancient times. The earth is our home. Now we regret what we have done to our home!

小题1:What’s the United Nations’ decision in the Four-Sided Talk?

A．Set an Earth Day.

B．Find out what is making the pollution.

C．Hold an international meeting.

D．Protect and love the earth.小题2:What doesn't the old tree tell us?

A．He’s afraid to be cut down some day.

B．The trees have the longest lives in the world.

C．Over-cutting teaches people a lesson.

D．People are destroying the natural environment.小题3:What will people do according to the passage?

① Over-use the resources. ② Beautify the earth.

③ Start a global group.   ④ Protect the earth.

A．①④

B．②③

C．①③

D．②④

同轴电缆是网络中应用十分广泛的传输介质之一，同轴电缆按照传输信号的方式可以分为______和______。