I would say B.
A, umm, don't crash trains, that's bad.
C, Lillian is wondering how fast a train can go, not at what curve will it fall.
D, Lillian isn't wondering about the size of the trains, just the speed.
Answer:
C- it help to show that some bacteria are just one cell.
Explanation:
Anton Leeuwenhoek was the first scientist who observed the presence of bacteria in his tooth scratch under the microscope made by himself. At that time there was no concept of bacteria and he named those small creatures as animalcules which were later termed as bacteria.
Leeuwenhoek during 1670s sent the details of his experimentation on algae and bacteria to Royal Society of London.
It was due to his that primitive experiment that made the discovery of bacteria and make it known to other scientists. Therefore option C is the best option that demonstrates that bacteria are single celled organisms that are very minute. When we look at cell theory there is a postulate that shows that cell is the fundamental unit of function and structure of all living organisms. So, the work of Anton Leeuwenhoek holds substantial importance in the formulation of cell theory.
Hope it helps!
Egeria densa is an aquatic plant which has developed different means of carrying out photosynthesis under conditions of low carbon dioxide. During the process, the plant generate low pH at the leaf surface during high light intensity and this acidification shift the process equilibrium towards carbon dioxide which will then diffuse into the cell through passive diffusion.
Thus, if the student place the plant inside her fresh water tank, the plant will increase the carbon dioxide content of the water, which will lead to an increase in pH and the increase in pH will negatively affect the fish.
Immigration followed by competition
I hope this right, if its not, sorry =)