A．ad(1) B．ad(2) C．ad(3) D．ad(4)

In March 1964，Alaska began to shake．There was a great earthquake．It was the biggest earthquake the country ever had．

Shops and houses fell down．One street dropped 3 feet．One island rose about 11 metres into the air．Parts of the sea bottom became dry land．People felt the earthquake hundreds of kilometres away．

Each year there are many earthquakes．Most of them are small，They happen in different parts of the world．We are not sure what makes them．But if you are near，you can see the earth move．You may see big crack(裂缝)in the ground．Sometimes the land drops on one side of the crack．It goes up on the other side of the crack．There is a new hill．The old world has a new shape．

49．From the story me can see_______．

A．most people are afraid of earthquake B．the bottom of the sea is nearly dry

C．people are trying to stop earthquakes D．earthquakes often do a lot of harm(损害)

50．We know from the story earthquakes happen________．

A．in shops and other buildings B．in different parts of the world

　　C．in small countries D．only in big cites

51．The story tells us________．

　　A．Earthquake changes the shape of the land B．houses fall down and streets are broken

　　C．Alaska shakes a lot D．how the strongest earthquake happened

　 Do you see many signs around you? Do you know the signs are all important part of our daily life? They can be in pictures or in words to give people information．What do people think are good signs? If you are thinking about making signs for others，what should you know?

　 The most important thing is that signs should be simple and easy to understand．Is is important to use clear language，On the other hand，the words should be easy to write and you just need to write down what you want to do，"Keep off the grass"is a very good example．It means"Don't touch or walk on the grass"．

Nowadays，there is a saying that"A picture paints a thousand words"．Perhaps that's why we are seeing more and more signs in pictures，or a combination(结合)of pictures and words．However，that's the difficult part，because picture signs may have different meanings in different countries．

52．First，a good sing should be________．

A．clear B．beautiful C．funny D．interesting

53．The writer uses"A picture paints a thousand words"to show that_______．

A．a word sign is as easy as a picture sign to make

B．a picture sign often has more information than a word sign

C．a word sign has more information than a picture sign

D．a word sign and a picture sign have the same information

54．What is the disadvantage(不利因素)of picture signs?_________．

　 A．They are too simple．

B．They ore not easy to understand．

C．They are not as interesting as word signs．