Answer:
Option (D)
Explanation:
In terms of chemistry, a catalyst is usually defined as the substance that is commonly used in a reaction in order to increase the rate of reaction, without getting consumed. It helps in the reduction of activation energy.
In the given case, the lever or a person can be considered as a catalyst because both of these will increase the efficiency (or rate) in removing the rock from the top of the perch. Thus, the lever or the human will remain the same after the removal of rock as a catalyst can be recovered after the reaction.
Therefore, the correct answer is option (D).
The brain and is divided into two parts called the left and right cerebral hemispheres. The two hemispheres are connected by the corpus callosum.
Dr. Brantz wants to test the part of the brain which is active while lying. For this purpose, he will need to make use of the fMRI (functional magnetic resonance imaging) technique. This technique is used for measuring the brain activity by the means of the detecting changes in the blood flow. The neural activation affects the cerebral blood flow, and this change can be noticed using fMRI.
Hence, the answer is 'fMRI'.
epidermis, dermis, subcutaneous fat
<span>the simplest sugars are generally called monosaccharides.
hope this helps</span>
