Some studies has shown that peppermint odor increases people’s mental sharpness, especially when they solve math problems. which statements below best describes that can possibly make this scientific claim valid? a. if it is tested in a controlled setting with repeated results. b. if the test is published on wikipedia. c. if the scientist was previously peer reviewed. d. if the math problems are easy problems

The answer is A.  This involves taking a good sample (using sampling techniques) of mathematicians or maths students and subjecting them to different treatments of peppermint before sitting them in a maths exam and examining the maths results. This should also be compared to a control group – not subjected to peppermint but also sitting them for exams- with which to compare the results.  

1 and 6 for apex

answer: the blood-brain barrier is a layer of specialized membranes and cell processes designed to keep undesirable substances from passing from the bloodstream into the precious tissues of the brain. while the blood-brain barrier does keep most bad things out of the central nervous system, it is not impermeable.

explanation: