The correct answers are:
– introduction of non-native species;
The invasive species are often very dangerous for the native species, and that is because they manage to out-compete them for the needed resources.
The pollution is a huge problem, as it is systematically destroying the environment, and the proper functioning of the ecosystems.
It is contributing to the lowering of the food sources for the wild animals.
– chemical agents;
Extremely dangerous, and poisonous for the plants and animals, either destroys their environment, or kills them directly.
– habitat loss;
The loss of the habitat effects every living organism as it is the place where they live and manage to function.