16．
　　How often do you see a plant you don't know about ?Your parents don't know it either. You can't always carry an encyclopedia with you. So maybe you would like to (1)       for it online with your smart phone. But where do you start?Now an app may help you (2)       the problem.
　　First, approach the unknown plant, but don't get too close. You can hold up your smart phone and take a (3)       picture of it. Then you submit (提交) the picture. After one to five seconds, the app will show the name of the plant and (4)      other useful information. For example:Where does this plant usually exist? Can it cause any harm to animals?Or can humans use it in some ways? The app (5)      can tell more than 4, 000 plants.
　　Cool, isn't it?Why not use it and share what you learn from it on WeChat Moments (微信朋友圈) You'll be one with the top brain in your class.

27．　　What is inside Mars (火星)? Perhaps I may give you the answer in the near future. I am InSight (洞察号). I am a spacecraft. On Nov 27, I arrived on Mars. In fact, I am the eighth spacecraft in my family to successfully land on Mars. But I'm the first to study the things inside it.
　　What do I look like? I have an arm, It is 1. 8 metres long. At work, if I need to move the things from my body to the ground, the arm helps me. On my arm, I have my single eye. You are right — it's a camera. I can use it to take pictures of Mars. As for navigation (导航), I will be led to the right place because scientists on the Earth keep telling me about directions. With three legs, I can stand well. And look at my two big "wings". Actually the get lots of power from the sun to make me work.
　　For the next 24 months — about one Martian year, I will stay on this red planet. Unlike brothers or sisters, I don't move a lot when I'm working on Mars. I will just stay at one place use my heat probe (探热仪) to explore nearly 5 meters deep inside Mars. This way, I can get a lot of information about the inside without damaging the planet. Then I will send the information back to Earth. This may help scientists find out how Mars started.

28．　　I come from a family full of love. Dad always has sports with me. Mum always gives me useful advice when I come across difficulties, but she is also a(1)      parent. When I was young, I had to earn my pocket money by helping with the housework.
　　One day after school, we walked by a bike shop and saw a kind of beautiful basket in the window:white, shiny, and decorated with flowers. I was(2)      by it at once. I decided to have it on my bike. "It's beautiful, " I pointed it out to my mother, "Mom, please, can I get it?I'll do more housework for as long as you say, but I need it. I really love it."
　　"You know, " she said, " if you save up, you can buy this yourself."
　　By the time I make enough pocket money, none will be(3)      !
　　"I will buy it for you, but you have to work for it," she said.
　　My mother bought the beautiful basket and kept it safely in a secret place I couldn't find. I washed dishes, tidied up the rooms, emptied the bins and even helped my dad clean the car. Each day, I counted my growing pocket money. After several weeks hard work, I jumped with joy. Oh, I made it (4)      ! I had the exact amount of money.
　　Another day, an unthinkable (难以置信的) thing happened, A neighbourhood girl rode by me with the exact same basket on her bike. Eight﹣year﹣old me cried and ran back home to tell my mother about the(5)      news.
　　And then came the lesson I've taken with me through my life. "Honey, it doesn't matter if your (6)      look the same. Yours is quite special because you paid for it yourself, "Mom said, carefully drying my hot tears.

29．　　When a man was walking by some elephants, he suddenly stopped. He wondered why these h(1)      animals were being held only by a small rope tied to their front legs. No chains, no c(2)      . It was clear that the elephants could break the rope at any time, but for some reason, they did not.
　　He saw a trainer nearby and asked why the animals just stood there and didn't try to get away. "Well, " the trainer said, when they were b(3)       elephants , we used the same rope to keep them from running away. At that age, it's enough to hold them. As they grow up, they are conditioned to believe they cannot break the rope. They believe it can still hold them, so they n(4)      try to break free.
　　The man was surprised. These animals could break free whenever they w(5)      , but because they believed they couldn't. Therefore, they were stuck right where they were.
　　How many of us go through life like the elephants? How many of us hold onto the belief that we don't have the a(6)       to do something just because we failed at it once before?
　　We should not give up trying when meet failures in life because they are a part of learning. If we failed once, it doesn't mean we can't succeed.

30．　　This is a story of a man who works in a big factory. He was a little bit weird(怪异的). He always wore an old red hat and carried a rubbish bag. He usually spent his break time and his lunchtime walking around in that old big factory and collecting used tins (铝罐).
　　One day, I was fixing one of the broken machines in the factory when this "tin man" came with his bag. As usual, he picked up the tins, which were all over the place. My manager was standing there , watching me.
　　When I finished my job, I heard my manager ask the "tin man" about what he was going to do with those tins he had collected. I didn't even think about this kind of question, because I always guessed that "tin man" would take those tins to the recycling center.
　　Unexpectedly (出乎意料), the "tin man" answered, "I will give these tins to my neighbor. He is too sick to work."
　　I was shocked to hear that, so I asked him: "You mean you collect all those tins just to help your neighbor?"
　　'I know this does not help much ," he said "He cannot work. He needs help and I have done everything I can for him."