Q4: Which of these human activities is most likely to cause the excessive
growth of phytoplankton in the world's oceans? *

A. The use of chemical fertilizers that are carried by runoff into rivers.

B. The logging of old-growth forests, which results in erosion.

C. The spraying of chemical herbicides that reduce carbon dioxide in the air.

D. The mining of fossil fuels, which requires digging underground tunnels

Which statements best describe the differences or similarities between a comparative investigation and an experimental investigation? check all that apply. experimental investigations are best for showing cause-and-effect relationships, while comparative investigations do not necessarily show this type of relationship. comparative investigations are often impractical and unrealistic, while experimental investigations are the most practical and realistic kinds of investigations. comparative investigations allow for the use of a wide range of variables but do not have a control group, while experimental investigations involve variables that can be controlled. both experimental investigations and comparative investigations are designed to answer scientific questions. both experimental investigations and comparative investigations focus on making observations rather than collecting new data.