Western states have spent a fortune trying to eradicate the tamarisk tree, which many experts believe hogs more than its share of water and damages the habitat of nativespecies.
西部诸州花了很多钱消灭红荆树，许多专家认为这种树会抢占过多的水，破坏本地物种的栖息地。
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In Hawaii, for example, a new pest-resistant species of papaya tree has been developed in response to ring-spot virus infections that have repeatedly damaged the native papaya-tree population.