Answer:
The fact that you have a task set in mind is something that can make you persist. The urge to satisfy your need to finish that task with the sharp tool is what drives you to persist with using the sharp tool knowing what could be the possible outcome of using it.
Explanation:
The controlled experiments are performed by the scientists, when they want to study the changes in the sample on changing a single variable. So, the correct answer is option (b).
In case, all variables are kept same, no changes would be observed in the experiment sample. A controlled experiment can be performed on living thing as well as non living. But, controlled experiment cannot be performed on the things which are influenced by a lot of variables, as they cannot create realistic results. So, the option (a), (c), and (d) are incorrect.
I believe that they’re norepinephrine (NE), and the acetylcholine (Ach). Hope this helps!
N colder near the poles go's with maritime/ polar air mass
