First discovered several years ago in North American lakes and rivers, the northern snakehead is a nonnative fish with no local predators. To keep the northern snakehead ’s population from growing, for the past three years wildlife officials have been paying recreational fishers for each northern snakehead they catch. In this way, the officials hope to stop the northern snakeheads from eliminating rare native fish species.
To evaluate the likelihood that the wildlife officials’ plan will succeed, it would be most useful to determine which of the following?
Whether the northern snakehead’s population in local lakes and rivers could be reduced by introducing predators from its native habitat
How local population numbers of rare native fish species have been changing since the wildlife officials started paying recreational fishers to catch northern snakeheads
Whether the fish species on which the northern snakehead preys in regions to which it is native and in which it is abundant have become significantly depleted in recent decades
What total number of northern snakehead have been caught by recreational fishers since the wildlife officials began paying for them
Whether rare native fish species in the region face any threats to their survival other than the proliferation of northern snakehead
为啥这题有两个目的:1是让这种鱼的数量不要增长了;2是让这种鱼不要再减少珍稀鱼了...
政府希望藉由減少snakehead的數量來達成「遏止snakehead殘害當地珍稀魚」的目的,因此最終目標只有一個。
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