Shlander is a man from space. He thinks the people and things on the earth are very strange. He is now writing a letter to his friend at home. Here is part of his letter. Read it and answer the questions. Now I am in a strange world. It is very nice. There are many new things here. There are many earth monsters   here, too. The earth monsters look very funny. They have just one head, two arms and two legs. They have thin black strings  on their heads. Some earth monsters have brown or yellow strings. The earth monsters have a hole in their faces. Every day, they put nice things and balls from the trees into the hole. They put water into the hole, too. The earth monsters do not walk very fast. They move from place to place in tin boxes. At night, the earth monsters like to look at a square window box. This box has very small earth monsters in it. The square window box is   _  .
a car or a bus a very small earth monster a TV set a radio