As is known to all, we live in a world of germs（细菌）. It is impossible to avoid exposure. Genetic makeups may give some people {#blank#}1{#/blank#} advantage over others. However, it does not stop people from becoming sick.

    All of us have been a victim of an {#blank#}2{#/blank#} (ill) at some point in our lives. Moreover, it is likely that we {#blank#}3{#/blank#} (get) sick again in the future. Our best chances of avoiding sickness {#blank#}4{#/blank#} (be) by exercising and employing good {#blank#}5{#/blank#} (habit).

    While good hygiene and exercise serve as obvious advice to most people, eating {#blank#}6{#/blank#} (healthy) is not always obvious. If you cannot define “healthy”, then your immune system will be happy {#blank#}7{#/blank#} (tell) you. The immune system is the foundation of our health. It works for us every day to keep us well. Ask {#blank#}8{#/blank#} (you): “Are you making its job easier {#blank#}9{#/blank#} harder?”

    Like any system, the immune system is not different. It has a tolerance too. If you eat unhealthily, your immune system will make you aware of it.

    Take a step in the right direction {#blank#}10{#/blank#} including some healthy food in your diet.

    It was {#blank#}1{#/blank#}(extreme) cold last Monday morning. While I was walking on my way to school, I noticed two street{#blank#}2{#/blank#} (clean) sweeping the street, across {#blank#}3{#/blank#}I walk every day. Seeing them {#blank#}4{#/blank#}(work) so hard on such {#blank#}5{#/blank#} cold morning, I was moved and made up my mind to do something for them. After arriving at school, I discussed with some classmates{#blank#}6{#/blank#} we could do. The next day, we got up early and prepared porridge at home. When we handed them the hot porridge and expressed our appreciation for {#blank#}7{#/blank#}(they) hard work, they looked a little {#blank#}8{#/blank#}(surprise) at first. And then they took the porridge, grateful {#blank#}9{#/blank#} our kindness. Although it was very cold, we all {#blank#}10{#/blank#}(feel) warm at that moment.

    As the effects of global warming, rising seas and natural disasters become more serious {#blank#}1{#/blank#} before, some local communities are taking action. Among them is one community in Florida {#blank#}2{#/blank#} local people and government officials are proving successful in protecting {#blank#}3{#/blank#} (coast) cities from the dangers of rising sea levels.

    The community has studied how much sea levels will rise and has suggested {#blank#}4{#/blank#} (way) to address the problem. It has persuaded the state government {#blank#}5{#/blank#} (ban) new developments on land near the coastline and recommended building sand dunes (沙丘) along beaches. Kristin Jacobs, one of the group's founders, decided to take action in 2008 after it became {#blank#}6{#/blank#} (gradual) clear that her state's 27 water authorities couldn't agree on joint (联合的) action.

    While some Florida government officials doubt whether the climate will become hotter or {#blank#}7{#/blank#} (cold), the people {#blank#}8{#/blank#} (live) in these locations are certain of the need to protect their communities.

    At present, coming up with ways to fight against the effects of climate change under an limited budget {#blank#}9{#/blank#} (be) a pressing concern. Only time will tell whether these coastal communities will succeed in {#blank#}10{#/blank#} end.

    When the construction of the new factory came to the end in {#blank#}1{#/blank#} European village, a pump was put in. Then, all the settlers {#blank#}2{#/blank#} (defeat) by a severe disease {#blank#}3{#/blank#} characteristic was similar to cholera. An expert physician who was instructed to attend to the victims and handle this case showed great enthusiasm, {#blank#}4{#/blank#} he didn't foresee that it was a hard challenge. After simple enquiry, he announced that it was the {#blank#}5{#/blank#} (pollute) water that made the people {#blank#}6{#/blank#} (suffer) from the disease. But without positive {#blank#}7{#/blank#} (evident), people suspected and rejected his view, {#blank#}8{#/blank#} (say) the theory he put forward made no sense. Being much {#blank#}9{#/blank#} (strict) with himself than before, he contributed himself to the case. Apart from making enquiries, he made detailed charts and analyzed the data carefully. Finally, he drew a scientific {#blank#}10{#/blank#} (conclude), linking the disease to the radium in the pump. He found out why people there got sick immediately.

    Every year, butterfly(蝴蝶) lovers in California go out in November to count monarch butterflies. They {#blank#}1{#/blank#}(get) a worrying result from their fall monarch count in 2018—{#blank#}2{#/blank#} number of monarchs had dropped by 86% since 2017.

The orange and black monarch butterflies are famous {#blank#}3{#/blank#} their long migrations(迁徙)—they fly thousands of miles every year. In the spring and summer they fly north; in the fall they fly south again.

    Monarchs, like most butterflies, are {#blank#}4{#/blank#}(terrible) important for plants. They help create more plants by spreading pollen(花粉) between plants. In turn, monarchs depend on plants for food. And they depend completely on a plant called milkweed {#blank#}5{#/blank#}(lay) their eggs.

    But monarchs have been facing growing problems for years. As more and more wild land has been turned into large farms, the monarchs have had trouble {#blank#}6{#/blank#}(find) enough milkweed. Many farms also use chemicals {#blank#}7{#/blank#} will kill insects in order to protect their plants. These chemicals also affect monarchs. Besides, pollution has made milkweed less {#blank#}8{#/blank#}(health) for the monarchs than it used to be.

    Scientists say monarchs will be in danger of dying out in the next 20 years if nothing {#blank#}9{#/blank#}(do) to save them.

   {#blank#}10{#/blank#}(thing) that people can do to help include planting milkweed, controlling the use of chemicals, protecting wild areas, and planting trees.

    One morning, I was waiting at the bus stop, worried about {#blank#}1{#/blank#}(be) late for school. There were many people waiting at the bus stop, {#blank#}2{#/blank#}some of them looked very anxious and {#blank#}3{#/blank#}(disappoint). When the bus finally came, we all hurried on board. I got a place next {#blank#}4{#/blank#}the window, so I had a good view of the sidewalk. A boy on a bike {#blank#}5{#/blank#}(catch) my attention. He was riding beside the bus and waving his arms. I heard a passenger behind me shouting to the driver, but he refused {#blank#}6{#/blank#}(stop) until we reached the next stop. Still, the boy kept {#blank#}7{#/blank#}(ride). He was carrying something over his shoulder and shouting. Finally, when we came to the next stop, the boy ran up to the door of the bus. I heard an excited conversation. Then the driver stood up and asked," {#blank#}8{#/blank#}anyone lose a suitcase at the last stop?" A woman on the bus shouted, "Oh dear! It's {#blank#}9{#/blank#}(I)." She pushed her way to the driver and took the suitcase thankfully. Everyone on the bus began talking about what the boy had done, and the crowd of strangers {#blank#}10{#/blank#}(sudden) became friendly to one another.