21．
　　What kind of meat do you usually eat? Most of us eat chicken, pork, or beef. But as the world's (1)       grows, more people will need protein. There won't be enough meat for everyone. And raising more livestock (家畜) will(2)       the environment. How can we solve this problem?
　　Scientists think that humans could eat more insects (3)      . Insects are healthy and nutritious. They have a lot of protein, healthy fats and vitamins. More (4)      , they are less harmful to the environment. Farmers don't need to clear forests to raise them. And raising insects will make fewer greenhouse gas emissions than raising cows.

22．
　　Have you ever thought about how astronauts wash their clothes without gravity (重力)? It's not easy. There's no washing machine on the International Space Station (ISS). Luckily, this may not be a problem in the future.
　　Russian scientists are making a (1)       washing machine for astronauts to use in space. The washing machine is different from the ones we use. It doesn't need water. It (2)       carbon dioxide from the air that the astronauts breathe out. Then, it uses high pressure to turn that carbon dioxide into a (3)       that can help clean clothes.
　　This could make astronauts' lives much (4)      . Because normal washing machines can't work in space, astronauts living aboard the ISS need to bring as many clothes as possible. Sometimes they even ask other spacecrafts to bring clean clothes from Earth.

38．　　The hot dog is popular. It's not a dog, but a cooked sausage in a long piece of bread. Here are some stories and facts about it.

39．　　You might have noticed that sometimes, when you're playing mobile games or taking a video call, the picture suddenly freezes because the network speed is too (1)      . When you try to download a movie on your phone, it seems to take forever.
　　These annoying things will soon become a thing of the (2)      , as China just issued commercial licenses (发放商用牌照) for 5 G networks on June 6, 2019. This means that China's telecommunications (电信) companies will be able to offer 5 G network speeds for mobile phone users.
　　The "G" in "5 G" (3)       generation (of mobile network technology). 1 G let us talk to each other. 2 G let us send messages. 3 G gave us mobile data and internet, and 4 G made all of these things faster. So what will 5 G bring?
　　First of all, 5 G is so fast that it will allow you to download an entire HD movie in seconds. The delay between sending and receiving data will be shortened. Now 4 G takes about 100 to 200 milliseconds (毫秒), while humans have a reaction time of about 200 to 300 milliseconds. But 5 G will get the delay down to 1 millisecond or less, which is almost real-time.
　　Because of this (4)       in speed, it will be possible to create and use new kinds of technology. Robots will be used to do operations because doctors will be able to control them from somewhere else without any delay. Self﹣driving cars will be able to run more (5)       because they can smoothly communicate with each other, traffic lights and road sensors (传感器).
　　5 G also makes the internet of things (IoT, 物联网) possible. IoT is a large network that connects nearly everything. (6)      , your toaster might be able to automatically start making your breakfast after your alarm clock rings.
　　All in all, 5 G will shape every type of technology that it touches. And you won't have to wait too long for that to happen.

40．　　A boy named Michael visited his grandparents on their farm with his sister, May. One day, Grandma gave him a slingshot (弹弓) to play with out in the woods. He practiced how to use it for some time but he still couldn't hit the target (目标) he set for himself.
　　Feeling a little u(1)      , he headed back to the farmhouse for dinner. On the way, he happened to see Grandma's pet duck. Just then, an idea suddenly came to his mind. He a(2)       at the duck with his slingshot and let it fly, hitting the duck in the head and killing it.
　　In a panic (惊慌), Michael hid the dead duck in the bushes, only to find that his sister was watching him all the time. May had seen everything he did, but she said n(3)      .
　　After lunch the next day, Grandma said, "May, let's wash the dishes. " But May said, "Grandma, Michael told me he wanted to help in the k(4)      . "Then she came close to Michael and whispered (低语), "Remember the duck?" So Michael did the washing.
　　Later that day, Grandpa asked if Michael and May wanted to go fishing, but Grandma interrupted, "I'm sorry but I need May to help me prepare for dinner." May just smiled and said, "Well, that's all right because Michael told me he wanted to help you. "Then she whispered to Michael again, "Remember the duck?"
　　So May went fishing and Michael stayed b(5)      to help make supper. After several days of doing both his chores and May's, Michael finally couldn't bear it anymore. He went to his grandma and told her the t(6)      that he had caused the death of her pet duck.
　　It really s(7)      Michael that Grandma just smiled and gave him a big hug. "Sweetheart, I know," said Grandma. "You see, I was standing at the window the other day and saw the whole thing, but because I love you, I forgave you. I just wanted to find out how long you would let May make a slave of you!"

41．　　My name is Opal. Last summer my daddy sent me to the store for a box of cheese, some white rice, and two tomatoes and I came back with a dog. This is what happened: I walked into the vegetable section of the grocery store to pick out my two tomatoes and I almost bumped (撞) right into the store manager. He was standing there all red﹣faced, screaming and waving his arms around. "Who let a dog in here?" he kept on shouting. "Who let a dog in here?"
　　At first, I didn't see a dog. There were just a lot of vegetables on the floor, tomatoes and onions and green peppers. It seemed that all the employees were running around, waving their arms just the same way the store manager was waving his.
　　And then the dog came running around the corner. He was a big dog. And ugly. And he looked like he was having a real good time. His tongue was hanging out and he was wagging (摇摆) his tail. He suddenly stopped and smiled right at me. I had never before in my life seen a dog smile, but that is what he did. He pulled back his lips and showed me all his teeth. Then he wagged his tail so hard that he knocked some oranges off a shelf, and they went rolling everywhere, mixing in with the tomatoes and onions and green peppers.
　　The manager screamed, "Somebody get that dog!"
　　The dog went running over to the manager, wagging his tail and smiling. He stood up on his hind legs (后腿). You could tell that all he wanted to do was get face to face with the manager and thank him for the good time he was having in the store, but somehow he ended up knocking the manager over. And the manager must have been having a bad day, because lying there on the floor, right in front of everybody, he started to cry. The dog came to him, really concerned, and licked (舔) his face.
　　"Please," said the manager. "Somebody call the pound (流浪狗收留所)."
　　"Wait a minute!" I shouted. "________."

42．Write at least 60 words on the topic "Warmth in winter". (冬日往往会令人联想到寒冷和不适. 当你遇到"冬天"的时候, 何人或何事让你感到温暖, 像冬日的暖阳照耀在你身上?请以"冬日里的温暖"为题写一篇不少于 60 词的短文, 标点符号不占格. )
The following words are just for reference:
difficulty unluckily brave
trouble unfortunately confident
注意:短文中不得出现真实姓名和校名及其它相关信息 , 否则不予评分.
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