30 PTS Please help I dont know the answer

What type of lipids are found in all biological membranes?

One statements is an example of a scientific observation. another statement is an example of a scientific explanation. identify the correct statement for each category to illustrate how scientific explanations are inferred from scientific observations.

Which of the following is a limitation of a clinical trial? a.)amount of random assignments b.)hospital cost c.)number of test tubes d.)amount of peer review