—No, it still remains {#blank#}1{#/blank#}.

    How will our continuously growing population affect our way of life, our environment, even our planet? No matter how you look at it, we will face {#blank#}1{#/blank#}extremely serious problem. By the middle of the 21st century, we {#blank#}2{#/blank#}(use) up all the oil that drives our cars if at the rate we're going. Even if scientists develop some new {#blank#}3{#/blank#}(way)of feeding the human race, the crowded conditions on the earth will make {#blank#}4{#/blank#}necessary for us to look for open space somewhere else. But none of the planets in our solar system are able {#blank#}5{#/blank#}(support) life at present. One possible solution {#blank#}6{#/blank#}the problem, however, has recently been suggested by an American scientist, Professor Carl Sagan. His idea is {#blank#}7{#/blank#}before the earth's resources are almost exhausted, it will be {#blank#}8{#/blank#}(total)possible to change the atmosphere of Venus（金星）and so create a new world almost as large as earth itself.

    However, {#blank#}9{#/blank#}his idea is turned into reality, humans have a long way to go. On the one hand, Venus is much {#blank#}10{#/blank#}(hot)than the earth; on the other hand, there is only a tiny amount of water there.

    On Aug 13，four Chinese irrigation sites won global {#blank#}1{#/blank#} (recognize)and were added to the 2018 list of Heritage Irrigation Structures， among {#blank#}2{#/blank#} Dujiangyan is the oldest and only surviving damless irrigation system in the world.

    Built over 2，000 years ago in {#blank#}3{#/blank#} is now Sichuan Province in Southwest China， this amazing engineering achievement is still playing a crucial role in irrigating farms and providing water resources for more than 50 cities in the province.

    In ancient times，the region in which Dujiangyan now stands {#blank#}4{#/blank#} (threaten)by frequent flooding from the Minjiang River. Li Bing，a local official of Sichuan Province at that time，together with his son，decided to construct an irrigation system on the Minjiang River {#blank#}5{#/blank#} (prevent)flooding. After many studies，they found the {#blank#}6{#/blank#} (simple)solution was to build a dam，but this would have ruined the Minjiang River. So instead Li designed a series of {#blank#}7{#/blank#} (channel)built at different levels along Mount Yulei that would take away the floodwater while leaving the river flowing {#blank#}8{#/blank#} (natural).Better still， the extra water could be directed to the dry Chengdu Plain，{#blank#}9{#/blank#} (make)it suitable for farming.

    Ever since the great Dujiangyan Irrigation System was completed， the Chengdu Plain has been free {#blank#}10{#/blank#} flooding and the people there have been living peacefully.

    Communicating with the old can be challenging, especially when considering the fact {#blank#}1{#/blank#} their abilities are failing.

    First of all, you are {#blank#}2{#/blank#} (suppose) to respect the old's thoughts, backgrounds and life experience. Do not correct their opinions even when you can't reach any {#blank#}3{#/blank#}(agree). And when old people are talking, listen {#blank#}4{#/blank#}(careful). Let them finish because letting them express their thoughts and emotions {#blank#}5{#/blank#}(be) important.

    When you're together with them, try to know if they would like {#blank#}6{#/blank#}(chat) or be quiet. And when you feel they want to be quiet, just be there, because{#blank#}7{#/blank#}(spend) time with them is as important as talking to them or cheering them up.

    As communication with old people can be difficult, it is {#blank#}8{#/blank#}(importance) to be always patient. When you are explaining something {#blank#}9{#/blank#} them, you should remain patient when they ask you to repeat yourself. Try using gestures while you talk with them, or write down what you want to say when {#blank#}10{#/blank#}is necessary.