Answer:
The correct option is A) It is not written by an authority
Explanation:
In the English language, credibility can be described as the quality of an object to be reliable or trusted.
A piece of written work which does not mention the name of the writer may be considered to be not reliable and trustworthy. Hence, the correct option is A.
Other options, like option D, is not correct because a peer- reviewed journal carries authentic information as the work has been rechecked by different people who have expertise on the subject.
The aqueous bromothymol blue solution act as a pH indicator and turns blue only in case when the pH of the sample is above or equal to 7.6
Since the pH of the water at the surface of the lakes is higher and ranges between 7.5 to 8.5 the color of bromothymol turn blue.
If a zebra mussel is discovered in a lake in Pennsylvania, then the ecologist would be worried because it is an invasive species. The zebra mussel is native to Ukraine and Russia, but if it has been found in Pennsylvania, than it means that it has been introduced in this area. As an invasive species, the zebra mussel can be very dangerous for the native species in the lake. The invasive species usually are more competitive for food sources than the native species, manage to reproduce quicker, bring in diseases, and the native species tend to not have defense mechanisms for them. This leads to rapid decline or even extinction in the native species, while the invasive spreads out quickly and takes over, resulting in dramatic change in the whole ecosystem.