I should think that Yolanda should use litmus paper throughout the reaction as its color will tell when the mixture is neutral and therefore then, when she can stop adding either the hydrochloric acid or the sodium hydroxide or if one or the other needs to be added to make the solution approach neutral. Blue litmus paper stays blue in a neutral solution, but will turn red in an acidic solution.
The statement that is true of cooling down after physical activity is that you should cool down for about 5 to 10 minutes after being physically active.
Local winds are driven by temperature differences in areas fairly close to each other. If water and land absorbed and released heat at the same rate, there wouldn't be any temperature differences and nothing to power local winds. See the related link for further information.
Answer: option D. the ratio of the population of male deer is not constant.
Explanation:
The bar graph permits to compare the results for two different populations: male and female deer in a very easy visual way.
These features are remarkable:
- The polulation of male deer (blue bars) decrease from 1961 to 1971, then increase in the next 10 year, decrease in the next decade, and increase for the next two decades. So, its trend is erratic, with ups and downs.
This discards the option A, which states that the population of male deer increases each decade from 1961 to 2011.
- The population of female deer (purple or brown bars) decreases every decade.
This discards the option B. which states that when the polulation of male deer increases, the poluplation of female deer also increases.
- The populations never are equal, hence this discards the option C.
- Since, one popultion increases and decreases, while the other population only decreases, you conclude that the ratio of the population of male deer to female deer is not constant, which is the option D.
