Answer :
Answer:
The non-native species are the prime threat to the surroundings as they can modify habitats and change the ecosystem services and function, and may replace or crowd-out the local species. The non-native species are considered as the second-ranked major threat to biodiversity after habitat destruction like deforestation.
Answer:
If you're only allowed to have one answer: They often use up resources that other organisms need.
If you can have multiple, then :
They often use up resources that other organisms need.
They easily contract and spread diseases to other organisms.
2nd and third ones are not really correct, and 1st one is better than the last one while the last one is also true.