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).
They are able to carry on photosynthesis longer then deciduous trees which lose thier leaves
A X-rays I think this is the answer
Ithe answer is b. and the temperature brought fires to the crops. One movie example of this could be the intersteller.
Answer: D, because in the text it said "pay for her influential impact".
I hope it helped if what i said made sense.. :D
