Question

introducing a new species into a delicate ecosystem can often be harmful. the common waxbill and other fruit - eating birds have established themselves on the hawaiian island of oahu after being brought there in the last 150 years. many plant species on the island rely on the activity of fruit - eating birds to maintain and increase their populations. in recent studies, common waxbills have been found to spread seeds of native forest plants that are at risk of extinction, such as the olomea shrub and the alahee tree, suggesting that
which choice most logically completes the text?
a non - native birds, such as the common waxbill, are unlikely to eat fruits from nonnative forest plants on oahu.
b non - native birds have had both positive and negative effects on oahus native plants.
c although non - native birds initially damaged the plants in oahus ecosystem, they are now proving useful to them.
d rather than harming oahus ecosystem, some non - native birds provide an important benefit on oahu.

Explanation:

The text starts by stating that introducing new species can be harmful. Then it gives an example of non - native common waxbills (fruit - eating birds) which have spread seeds of native plants at risk of extinction. So the overall idea is that these non - native birds are providing a benefit.

• Option A: The text is about native plants and non - native birds' role in their survival, not about non - native plants. So this option is out of scope.
• Option B: There is no mention of negative effects of non - native birds on native plants in the text. The text focuses on a positive aspect (seed - spreading).
• Option C: There is no information in the text about non - native birds initially damaging the plants. The text only presents a positive role (seed - spreading) for the non - native birds.
• Option D: This option aligns with the text. The text shows that non - native birds (common waxbills) are providing a benefit (spreading seeds of native plants at risk of extinction) rather than just being harmful.

Answer:

D. rather than harming Oahu's ecosystem, some non - native birds provide an important benefit on Oahu.