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Humans are responsible for causing changes in the environment that hurt animals and species(物种)。We take up more space on Earth for our homes and cities. We pollute habitats(栖息地). 48 illegally hunt and kill animals. All of these activities take resources and habitats away 49 plants and animals.
Hunan activity often changes or destroys the habitats that plants and animals need to survive. 50 human populations are growing so fast animals and plants are disappearing many times faster51 they have in the past 65 million years.
Animals and plants have always had a 52 time surviving. Animals became extinct in the past for a wide variety of reasons. In some cases, petition for resources among animals led to extinction and in 53 cases, environmental changes caused extinction.
Fortunately, we humans are beginning to realize our mistakes, 54 we could destroy everything on Earth. We must not only use our knowledge and abilities to manage the Earth,55 to make the Earth a safe and healthy place where all animals and plants—including humans ourselves –can live.48.we 49.from 50.because / as / since 51.than
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(答案→)48.we 49.from 50.because / as / since 51.than
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