The introduction of foxes in order to control, or even decline, the rapidly growing rabbit population was not effective due to very simple reasons, reproduction rates and available area for living.
The rabbits are reproducing quicker than the foxes, and not just quicker, but in larger numbers with every lither, thus outnumbering the foxes by far, even if each fox manages to kill a rabbit or two each day.
The area available for the rabbits to live and spread out is huge, so they are not limited by a small amount of area where their number will have to stop to grow because of lack of food sources, thus spreading around without any problem, especially because of the lack of competition.
Answer:
The correct answer would be A. crust.
The crust is the outermost layer of the earth which is composed of different types of rocks such as sedimentary, metamorphic, and igneous rocks.
It is completely solid and can be broadly classified into two types: continental crust and oceanic crust.
The thickness of the oceanic crust is about 5 km to 10 km. It is primarily composed of basalt, gabbro, and diabase.
The thickness of the continental crust is around 30 km to 50 km.
The crust forms lithosphere along with hard and upper mantle.
Positive feedback is a control system that sends a signal to ( increase) a response.
We could possibly use water as a fuel source, rather than fossil fuels (which are limited)
Science has already developed something of the sort, and with using water as a fuel source for say vehicles and such, it's inevitable for a positive change to happen because there would be less carbon monoxide; which means less polution.