题目

如图所示，AB是物体，A′B′是物体经过凸透镜所成的像，CD为透镜的主光轴，试画出凸透镜的大致位置。 答案：解：如图所示：语法填空 阅读下面材料，在空白处填入适当的内容（1个单词）或括号内单词的正确形式。I wanted to do something special for my 15－year－old son, who has always been a perfect boy. He worked all summer to earn enough money to buy __【1】__(he) a new racing－bicycle instead of asking for money from me. Then he spent hours and hours on it. I loved my son so much __【2】__I bought him a pair of sunglasses and gloves. When my son rode the racing－bicycle with them, he looked very cool. He dreamed _【3】__ taking part in a race and winning.On November 10th, my birthday, when I went to the kitchen to start the milk and bread in the morning, I found _【4】__ beautiful guitar on the table, beside which was a card, __【5】__(say), “Happy birthday to my wonderful mother.” I was surprised and then began to sob. I remembered once I __【6】__(joke) to my family that I wanted to learn playing the guitar to make my life colorful. I had __【7】__(forget) it, but my son remembered. He took it __【8】__(serious), and bought me one as a birthday gift. When I wondered _【9】__ my son could buy this expensive gift, soon I realized that my son had sold his racing－bicycle __【10】__(get) me the guitar.