关于点电荷，下列表述正确的是（　　）.

在一对相对性状的杂交实验中，子一代（F₁）未表现出来的亲本性状称为（    ）

   In many high schools，there are strict rules about using mobile phones. If your phone rings in class，for example，the teacher will be very angry.
   Every mobile phone has a ringtone (铃声). It tells you that someone is calling you. Now，there is a ringtone called “mosquitotone (蚊子铃声)”. Using it，students can receive calls and text messages (短信) in class but the teacher will not realize what is happening. How?
   Mosquitotone has a special sound. Only children and teenagers can hear it. As we get older，we are unable to hear some sounds with high frequencies (频率). As a result，a child or teenager can hear the mosquitotone ringtone, but it's_inaudible_to someone 20 or older.
   But sometimes，people over 20 can hear the ringtone. One British student's phone uses mosquitotone. In class，the student's phone rang. The 32­year­old teacher looked at the student and became unhappy. “I heard that. You know the rule：no mobile phone in class.”
   Not all the students are interested in mosquitotone. Jerry Jones，a high school student of 17，says，“Using mosquitotone too often is bad for our hearing. I may use it for pleasure，but not in class. It's unfair to the teachers！”
   What do parents think of mosquitotone？“I think it is perfect for places like movie theaters，” says Connie Neeson,44.“Think about it. Yon're watching a film and someone's mobile phone rings. Mosquitotone is good because many people don't hear it. However，it also has a bad influence on their study if students use it in class.”

   Many years ago there lived two brothers in London. They were both very rich. They had  1  ideas about money. They were quarrelling（争吵）about what would happen if a poor man could 2  a million pound note. One thought that anyone with such a note would have  3 he wanted; the other thought that it would be  4 for him to get anything with the note（钞票）.They couldn’t agree with each other. So they 5  to make a bet (打赌).
   It happened that a young man named Henry was wandering through the street that day, who had come to Britain only chance.  6 home and job, he looked pale（苍白的）and  7 . Suddenly he saw an apple  8  away by a child. The man was so hungry that he was thinking of picking it up to eat. Just as he was  9 out his hand, he heard a voice calling him. He looked up and saw the two  10. They gave him an envelope. They told him not to open it until two o’clock. They said, “Nothing but money in it.” Then they lef.