Question

introducing a new species into a delicate ecosystem can often be harmful. the hwamei 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 have been found to rely on the activity of fruit - eating birds to maintain and increase their populations. in recent studies, hwameis have been found to spread seeds of native forest plants that are at risk of extinction, such as the kawau tree and the alalhee tree, suggesting that — which choice most logically completes the text? a non - native birds have had both positive and negative effects on oahus native plants. b although non - native birds initially damaged the plants in oahus ecosystem, they are now proving useful to them. c rather than harming oahus ecosystem, some non - native birds provide an important benefit on oahu. d non - native birds, such as the hwamei, are unlikely to eat fruits from non - native forest plants on oahu.

Explanation:

The text first mentions that introducing new species can be harmful to an ecosystem. Then it talks about non - native fruit - eating birds like hwameis on Oahu. It says they have been found to spread seeds of native plants at risk of extinction, which implies a positive effect on the ecosystem in terms of plant population maintenance. Option C is correct as it states that rather than harming Oahu's ecosystem, some non - native birds provide an important benefit. Option A only mentions non - native birds having positive and negative effects without emphasizing the benefit part as strongly as C. Option B focuses on the initial damage and current usefulness which is not the main point. Option D is about non - native birds not eating non - native plants which is not relevant to the overall message about the benefit of non - native birds to the ecosystem.

Answer:

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