Researchers grew populations of identical E. coli bacteria in a growth medium that contained a low concentration of glucose and a high concentration of citrate, a substance that is not typically consumed by E. coli. For thousands of generations, the bacteria used only glucose as an energy source and grew relatively slowly and to a low density because of the low concentrations of glucose. After about 30,000 generations, one population emerged that began to rapidly grow to a much higher density. The researchers hypothesized that the bacteria evolved the ability to use citrate as an energy source and referred to the as Cit+. To test the hypothesis, the researchers grew separate populations of the Cit+ bacteria and bacteria from the original population (Cit-) in a growth medium that contained only citrate. (a) Describe one outcome that would demonstrate that a given population has evolved.
(b) Identify the dependent variable measured in the experiments.
(c) Predict the results obtained by the researchers when they grew the Cit+ and Cit- bacteria in medium that contained only citrate.
(d) Provide a reason to support the idea that the researchers claim that the Cit+ mutation increases the fitness of the bacteria.

the correct answer is - d. china has a large and growing population.

the fact that china has a large (the biggest) population, and it is still growing, doesn't hinder the agriculture production in the country. in fact, it can for increased production in the agriculture, since there's more labor force, as well the sheer mass of people produces lots of scientists that come up with new inventions as to how to improve this sector. nice example is the inner mongolia region in china, in general dominated by the gobi desert, but few scientist came up with a nice idea as to how to make the region productive by using plants that are very resistant to droughts, so lots of people have been employed, and the region is becoming greener and greener each year, and the production of food in this region is also increasing.

answer-

the statement that f(x) = |x+a| + b has exactly one x-intercept is sometimes correct.

solution-

it solely depends on b, whether the function will have one or two or zero x intercept.

this plot of the given function, f(x) = |x+a| + b will be the basic absolute value graph i.e v shape, with vertex translated to (-a, b), instead of origin.

1-   if b is zero, the graph will have exactly one x-intercept, at x= -a

2- if b is positive, the whole graph will be above the x-axis, hence it will have no x-intercepts.

3- if b is negative, the graph will be below the x-axis, hence it will have two x-intercepts.

∴ the statement is sometimes true.

bal is blood alcohol level. bac will normally be higher in a person with more body fat. so the answer to your question would be, as body fat decreases, the increasing rate of bal decreases.