Andy rode slowly on his way to school，day-dreaming about the fishing trip that his father had promised him．He was so busy dreaming about all the fish he would catch that he was unaware of everything else around him．

He rode along until a strange sound drew him to the present．He came to a stop and looked curiously up to the sky．What he saw shocked and terrified him．A huge swarm of bees filled the sky like a black cloud and the buzzing mass seemed to be heading angrily towards him．

With no time to waste，Andy sped off in the opposite direction，riding furiously-but without knowing how to escape the swarm．As the bees came closer，his panic increased．Andy knew that he was sensitive to bee stings（蜇）．The last sting had landed him in hospital-and that was only one bee sting!Suddenly，his father's words came to him．"When you are in a tight situation，don't panic．Use your brain and think your way out of it．"

On a nearby hill，he could see smoke waving slowly skywards from the chimney of the Nelson family home．"Bees don't like smoke，"he thought．"They couldn't get into the house．"But Andy knew he could not reach the house in time．He estimated that the bees would catch up with him soon．

Suddenly，out of the corner of his eyes，he spotted a small dam used by Mr．Nelson．Off his bike and into the cool water he dived，disappearing below the surface and away from the savage insects．After holding his breath for as long as he could，Andy came up for air and noticed the bees had gone．Dragging himself out of the dam，he struggled up the hilly slope and rang the doorbell．Mrs．Nelson took him inside and rang his mother．

21．Why did Andy fail to notice the swarm of bees earlier？___

A．He was riding to school．

B．He was listening to a strange sound．

C．He was going fishing with his father．

D．He was lost in the thought of the fishing trip．

22．Which of the following is NOT mentioned abo