Which ecosystems do not have symbotic relationships
a. deserts
b. all ecosystems contain symbotic relationships
c. tropical rainforests

Why are carbon dioxide concentrations expected to increase? a carbon dioxide concentrations are expected to increase, because fossil fuel burning is expected to increase b. carbon dioxide concentrations are expected to increase, because of an increase in agriculture. c. carbon dioxide concentrations are expected to increase, because more land will have to be cleared for increasing populations and agricultural use. d. all of the above select the best answer from the choices provided mark this and return save and exit next submit submit

Someone with these questions! pls 30 pts

Select all the correct answers. for a claim about the natural world to be considered scientific, what attributes must it have? a). it must be open to modification if new evidence doesn't completely support it. b). it must be based on scientific observations that can be repeated in a controlled setting. c). it must be applicable to future events and occurrences. d). it must be consistent with only a small portion of relevant observations or data.