The lecturer opposes the points in the reading passage from three aspects. She considers all methods listed in the passage are useless or causing more disadvantages.
First of all, the national fence will do little to the controlling of toads. Because even the fences are set everywhere, there are still many rivers and streams which cannot be controlled by the fence. The toads can lay their eggs in these water flow can be carried from one place to another. Besides, young toads can also stay in these dynamic streams. Only a minor part of toads will be impeded by national fences. So the fence doesn't work.
Secondly, the volunteers' activities may have resulted in successful traps. However, these volunteering will have more negative effects for the reason that volunteers are not professional. So it is not easy for them to distinguish between native frogs and the toads, especially when toads are young, which can lead to the consequence that native frog species will suffer a lot. In this way, volunteers' capture is still not a helpful method.
Thirdly, the virus mentioned in passage can be harmful to the native toads in America. The toads in Australia not only stay there but also can be transferred to other continents by researchers and pet collectors. If the virus is carried by those toads transferred to America, it will cause severe damage to the native toads there. Thus, the ecological balance in America will also suffer a lot for that the toad plays an important role in ecological system there.
In conclusion, we can see that all of the ways listed in the reading passage are ineffective. Harmful results may even bring about by them. Thus, we cannot use them to control the toads' proliferation in Australia.