科普英语辩论陈词.docx

(1) Bees and NeonicsThe advantages of Neonics: First, they can be used on a vast majority of plants, including 95% percent of corn and the canola crops, fruits and vegetable crops. Second, they are effective against many insects, including the sucking insects, some chewing insects, soil insects and are also used to control fleas on domestic animals.Third, most neonics are water-soluble and break down slowly in the environment, so they can be taken up by the plant and provide protection from insects as the plant grows.The consequences of using neonics:It was pointed out by plenty of studies that the wide use of neonics has caused a great deal of bees deaths. It is believed that the residues of neonics on the plants have impacted bees ability to forage, learn and remember navigation routes to and from food sources. As a result, a phenomenon called Colony Collapse Disorder appeared, and this has lead to a massive loss of bees. Furthermore, more plants are supposed to die because the lack of pollinators. In addition, it would impact our human beings. As a matter of fact, among the 1300 species of plants which are useful to humans, 1100 species require pollination by the bees. So if we use the neonics, we will not only cause terrible ecological problems, but also cause disastrous economic loss.(2) BiodiversityExtinctions are bad, we have the responsibility to protect biodiversity:Biodiversity is important to ecological stability, and this will be threatened by excessive species extinctions. Every species is closely related to other species. This is to say, if one species becomes extinct, others will be affected. For example, frogs will find difficulties in finding food if the flies become extinct. And step by step, if a large amount of species become extinct, finally we human beings will be affected. We feed on and rely on other species. It would be impossible for us to survive on the earth without them. So we have the responsibility to protect the biodiversity, not only for the animals, but also for ourselves.Furthermore, it is because of humans that many species become extinct. We cut down the forests, let out the poisonous gas, emit the contaminated water into rivers and so on. All the things we did made many species homeless. And therefore, they become extinct. Every species on this earth have the equal right to live, it is against the ethics to deprive other species right.Extinctions are not bad, we neednt protect biodiversity:The idea that extinctions will lead to ecological disaster is an exaggeration. Fossil evidence shows that mass extinctions have occurred many times throughout the history of life on earth, one of the most recent being the mass demise of dinosaurs. After every collapse of biodiversity, it subsequently rebounded, with the earth coming to no lasting harm. Extinctions are simply part of the natural evolutionary process. Since the very beginnings of life, nature has operated by the Darwinian principle of “survival of the fittest”. Life forms that cannot keep up with the environments change deserve to die out and be supplanted by others. Although we human beings are the smartest creatures on the earth, we cant violate the natures rules.(3) EnergyThe advantages and disadvantages of fossil energy and new energies:1. Fossil energy is reliable while most of the new energies cant offer constant energy supply.2. Fossil energy will be used up within four to five decades while most of the new energies are renewable.3. Fossil energy pollutes the environment while most of the new energies are environmentally-friendly.4. New energies are not efficient enough to replace fossil energy in many aspects.The main new energies: solar energy, geothermal energy(地热), wind energy, tidal energy(潮汐), nuclear energy and hydropower.Solar energy:Advantages:1、It is available everywhere in the world.2、It will not cause any pollution.3、The amount of energy which reaches the earth is equal to 130 trillion tons of coal each year.4、It will not be used up in billions of years.Disadvantages:1、It is greatly affected by the weather. It will not be available in rainy or cloudy days.2、It is greatly dispersed and difficult to collect.3、It is not efficient enough, the cost of it is too high.Geothermal energy:Advantages: 1、It causes no pollution.2、Geothermal power plants are self-sustaining, powering itself after it has been activated. 3、Once operational, they also produce power at a 90 percent efficiency rating.Disadvantages:1、It has geographical limits.2、The cost is very high.Wind energy:Advantages: 1. Renewable and pollution-free.2. Needs lesser space for installation.3. Cost-effective source of energy.4. Ideal for countries with infrastructural issues.Disadvantages1. Unreliable source of energy.2. It is expensive to store.3. Poses threat to wildlife, especially, birds and bats.Tidal energyAdvantages: 1.Environmentally-friendly.2. It is a reliable source of energy as the tides are easy to predict.3. It may protect the coastline from high storm tides.Disadvantages:1.It has geographical limits. (Not available inland)2.The tidal barrages are expensive to construct.3. It may cause problems to the marine animals and affect the climate.Nuclear energyAdvantages:1. One kilogram of uranium-235 approximately produces as much energy as 1,500 tons of coal does.2. Emit no greenhouse gases.3. It may help some countries on fuel independence.Disadvantages:1. It increases the possibility of accidental release of radiation.2. It is nonrenewable and will be used up in about 100 years time.3. The nuclear waste is highly poisonous and radioactive.4. Some countries may try to develop nuclear weapons.Hydropower energy:Advantages:1. Environmentally-friendly.2. Renewable.3. It is generally available as needed.4. It may bring benefits to water supply and flood control.Disadvantages:1. Animals which live in the water may be affected as they will not be able to migrate. 2. It may be impacted by droughts.3. It has geographical limits.4. The hydropower plants are expensive to build.(4) Space ScienceQuestion: Is it necessary to spend so much money on space exploration?Yes:1. Space exploration may one day save mankind from becoming extinct. Since the resources on the earth will one day be used up and the existence of thousands of near-earth asteroids, we will need to immigrate to another planet one day. To discover the planet and succeed in immigrating, we need to work for quite a long time. As the old Chinese saying goes, “If one has no long-term considerations, he can hardly avoid trouble every now and then.”2. The exploitation of space has directly changed our world. (Satellites enable us to contact with people far away. The GPS enables us to pinpoint our location. Weather satellites give out the warnings which save hundreds of lives each year.) 3. Space exploitation has spawned many scientific innovations. lThe need to reduce weight on rockets led to the inventions of micro-chip and the modern computer. The need to protect astronauts led to development of suits suitable for extre