It means to change the looks of the landscape. Or changes in the landscape.
Eliminate B and D, not all single celled organism carry out through photosynthesis , they called singled celled organism and not work with other cell, it's either A and C, single celled organism is not a complex organism. so you can eliminate letter C.
so the best answer is A, although they have multiple organs system to maintain their internal stability.
The answer to this question is Speciation
When biogeographic isolation happen, the population of a certain species will be totally isolated (separated) from other species, which cause that population unable to cross-breeds with other species. This will form a unque and special species because that population will always maintain a certain characteristic unlike other population that are forced to cross-breed
Avoid carcinogens (like smoking residues..etc), eat healthy and sleep well in order to maintain a strong immune system
Answer:
yes because all is caused from the over use and exploitation of harmful gasses like CO2.
Explanation: