An example of something that does not have mass would most likely be air. Because in order for something to have mass, it must take up space and have shape. Anything that you can think of that does <u>not</u> have <u>space or shape</u> does not have mass.
One possible strategy would be to find the cane toads natural predators. if the cane toad does have natural predators, then it can control the population by hunting it and etc. one limitation to this however would be that there has to be an balance between the toad and that natural predator. for example, they need to survive off of each other so there can’t be too many of the toads not so many natural predators and vise verse. (i hope this makes sense i took bio last year)
Stereomicroscopes is that they have a much lower magnification limit than other microscopes, such as the compound microscope, for instance. The stereomicroscope can magnify an image 100-150 times, while normal compound microscopes can magnify an image 1000-1500 times. This can be a disadvantage of stereomicroscopes, because not as much detail of the image is seen.
The correct answer is 4.) Eventually they become separate species
A process of formation of a new species from an existing species is called speciation.
When a single species changed into two or more separate species, is called speciation. Speciation can take place due to reproductive isolation. In reproductive isolation, the separated species no longer can interbreed among themselves. This is happened due to mating differences, sterility or environmental barriers which finally results into the adaptive splitting into two species.
The answer is actually 4.4 billion years, but i guess you can estimate to 4.5
