Recently, my mother asked me to drop off some letters at the post office and pick up some stamps for her. Without giving it a thought, I took the letters and purchased her stamps.

    A few days later, she mentioned that one of the letters I had mailed was missing a stamp, and asked me if I had put a stamp on it. She had remembered asking me to put a stamp on it, though I certainly had not heard her. So, unfortunately, it looked like the letter, which was a bill of course, would come back marked "Return to Sender for Insufficient Postage". A few days went by and I returned to the post office to pick up our mail. While I was there, I saw the postmaster and happened to tell him about Mom's letter missing the stamp. I asked him to be on the lookout for it coming back. It was then that he told me his story. "You know," he said, "I immediately saw after you had dropped the mail off that your letter was missing a stamp. I also noticed that it was a bill for a credit card company. I thought to myself that you have always been kind to me and my partner, and I wanted to return the favor. So, to prevent your mother from getting charged a late fee from the credit card company, I took money from our change dish (extra pennies for folks who need one), and purchased a stamp for you."

    When I heard it, I couldn't believe it. What a blessing that was! I thanked him over and over again for putting the stamp on the letter for us. Then, I immediately dumped(倾倒) all the change out of my purse and into the penny dish in order to help others out in the future. When I got home, I was able to tell Mom the good news. This was kindness karma(因果报应) in action, I believe!

    As I walked into the primary school, I looked down at my new black Mary Jane shoes—I wanted to be anywhere in the world but Fountain Inn Elementary School. I stood at Mrs. Blackstone's door. Before I tried the1, the wooden door suddenly opened. "We've been waiting for you!" Mrs. Blackstone, my new fifth grade teacher said at an unusually2voice. With a smile my mom walked away and I was left3in front of a group of students.

    Over the next few days, Mrs. Blackstone made it her4to find me a new best friend and help me join a choir（合唱队）. During history5, when I sat down at my desk6I didn't want to speak in front of the class, she would not only call on me but have me stand up to7my classmates. She laughed at my nervousness when I wouldn't get in line to sharpen my pencil 8being embarrassed. Her silliness made me smile and finally feel9in the new environment.

    One spring afternoon, Mrs. Blackstone 10me to stay after class. "I'd like to speak with you, Amanda." My mind 11. Had I made a bad grade? Had I hurt someone's feelings? "Are you enjoying your new school?" she sat comfortably behind her desk, "I want to tell you12, between you and me, not to be shared with anyone else." "Okay." My throat 13felt very dry. With her14raised, she said, "I see something15in you. I've been a teacher for over twenty-five years; I can16it. But you17believe in yourself. That's very important. Remember that and you'll go18."

    Her voice was19to my ears that day. I walked out of her class,20staring at my Mary Jane shoes. My teacher saw something special in me!

李拯参军前是个勤奋好学的学生，复员后到电厂努力工作，多次被评为劳模。他每月给乡下年迈的父母寄300元，并自觉交纳个人所得税，这表明他履行了（    ）

①受教育义务       ②劳动义务      ③教育未成年子女义务    ④依法纳税义务

⑤赡养父母义务  ⑥依法服兵役   ⑦计划生育                        ⑧爱护公物

忽略空气阻力，抛出后的小球在空中运动轨迹如图所示，抛出后的小球由于（   ）