广播是通过话筒把声音信号转换成 ____，又加载到高频电磁波上，再通过 ____发射到空中，由收音机接收还原成声音．

    A group of old classmates, who have succeeded in their work, got together to visit their teacher. The conversation soon turned to complaining about the stress in work and life. Offering his guests coffee, the teacher went to the kitchen and returned with a large pot of coffee and many cups-china(瓷),plastic and glass, some plain(朴素的）looking,some expensive and some lovely.The teacher told them to help themselves to the coffee.

    When all the students had a cup of coffee in hand, the teacher said,“Can you notice all the nice looking expensive cups were taken,leaving behind the plain and cheap ones? While it is normal for you to want only the best for yourselves, that is the source(根源）of your problems and stress.”

    “What all of you really wanted was coffee, not the cup, but you went for the best cups and were eyeing(注视)each other's cups.”

    “Now think about this：life is the coffee, and the jobs, money and position are the cups. They are just tools to hold life, and do not change the quality of life. Sometimes, we just care about the cups, and we fail to enjoy the coffee. So don't let the cups drive you, enjoy the coffee instead.

①自习课上，同学们安静地学习

②一个小女孩在个人独处的场合将果皮扔进垃圾箱

③一位男生躲在校园的角落里吸烟

④非得在老师的监督下才完成作业

    When we talk about our grandparents, the first word we can remember is "old". Super Grandmother and Super Grandfather contest (比赛) gives old people a chance to show their talents to us. What is this contest like?

    Every year, people aged over seventy, from all over Georgia, come to Tbilisi to take part in Super Grandmother and Super Grandfather contest. Some play the piano, some dance, some sing and some perform plays. Although they are very old, they perform very carefully. In fact, some of their programmes are good and they are even invited to television shows.

    In this year's contest, 80-year- old Tsuri Kakabadze got the title of "Super Grandmother" because she had a beautiful voice. And 77-year-old Yuri Merabov got the title of "Super Grandfather" because he played the piano well.

    But the results do not really matter. These old people just come to have some fun. I hope this kind of contest should be all over world. Don't you?

地球上很多山脉、火山、地震的形成与板块的运动有关，下列叙述错误的是（    ）