Final answer:
To extract algae, carbon dioxide can be used as a solvent, an oil press can extract oils directly, and microwave-assisted extraction can help in breaking down cell walls.
Step-by-step explanation:
In response to the question on which methods can be used to extract algae, several techniques may apply, but not all of the options listed are appropriate for algae extraction.
In particular, (B) using carbon dioxide as a solvent, (C) an oil press, and (F) microwave-assisted extraction are viable methods for obtaining substances from algae. Carbon dioxide can be used in supercritical fluid extractions, an oil press can physically extract oils, and microwave-assisted extraction can rapidly heat and breakdown cell walls to release contents.
Conversely, (A) washing under water, (D) burning, and (E) using a chemical solvent are less relevant or incorrect in the context of algae extraction. It's important to ensure extraction methods are efficient and maintain the integrity of the algae's bioactive compounds.