A sand castle was changed by the ocean waves would be slowly taken away by the waves and would just become a smooth mound of sand. If someone stomped on it then it would still have the same amount of sand as before but in a different shape.
It’s A: C2H2N (basically you count how many C, H and N there are)
Answer : Option B) Attempt to control the conditions.
Explanation : While conducting an experiment, a scientist should always attempt to control the reaction conditions.
If the reaction conditions are not controlled one can lose the expected result or observation that was supposed to be generated from the experiment. Like controlling the given temperature, pressure, addition of catalysts, etc. If these conditions are overlooked one may not achieve the expected results and will not reach to the conclusion.