完形填空（共15小题，每小题1分，计15分）
阅读下面短文，掌握其大意，然后从各题所给的四个选项中选出一个最佳答案。
The little boy entered the house, unhappy. His mother was      cakes in the kitchen. She smiled as she     , but stopped when she saw his face. "Tyler,      happened? Is everything okay?"
"Nothing is okay, mom." said the boy," Today, in our science lesson, Mrs. Green was talking about the        . She said that the whole world is getting dirtier and that many animals and plants are dying. She wants us to think of something we can do to help. I thought all the way, but there is        I can do to make a difference. "
"Let me tell you        ." the mother said after thinking for a while. "One morning a man was walking down a beach, there he saw thousands of       starfish covering the beach, they were pushed up by the waves(浪), and it was too far up for them to make their way back by        .The man shook his head as he walked along, 'What a pity! So many starfish will die on the beach.' The man felt very sorry         those starfish. He went on walking and just at that time he was        to find a boy in front who was throwing the starfish back into the sea as         as he could,' How silly you are! My        ,' the man said, 'There are so many starfish, can you throw all of them back？' The boy didn't stop but kept throwing,'         I can't help them all I can make a difference to this one, and this one, and this one, and this one. "
"Thinking for a moment, the man        to help return the starfish to their home. He smiled and said to himself, ' Sometimes the biggest lesson in life comes from the        person. "

A．drinking B．making C．selling D．washing

A．turned on B．turned down C．turned around D．turned off

A．what B．when C．where D．why

A．air B．land C．water D．environment

A．something B．anything C．everything D．nothing

A．a lie B．a story C．a joke D．a truth

A．died B．dead C．dying D．death

A．himself B．itself C．ourselves D．themselves

A．for B．of C．from D．forward

A．afraid B．surprised C．sad D．angry

A．slow B．low C．fast D．high

A．father B．mother C．son D．daughter

A．Or B．So C．Because D．Though

A．began B．continued C．forgot D．waited

A．shortest B．tallest C．smallest D．biggest