Answer:
Scientist 1
Explanation:
<em>The conclusion of scientists 1 is valid.</em>
Human activities such as burning of fossil fuels, agriculture, deforestation, etc. leads to the emission of carbon in the form of carbon dioxide into the atmosphere. <em>An increase in the population of a city will only lead to an increase in these activities and hence, an increase in the amount of carbon emitted into the atmosphere.</em>
Also, volcanic activities leads to the production of volcanic gases which is a mixture of carbon dioxide, oxides of sulfur, nitrogen, etc.
<u>However, an active volcano that is several miles away from the city might not be a major source of carbon in the air above a large city. The carbon dioxide produced from such volcanic activity thins out before reaching the city.</u>
Answer:
a) the oxidizing agent.
Explanation:
In the citric acid cycle, malate is dehydrogenated into oxaloacetate and the reaction is catalyzed by malate dehydrogenase. The released electrons are accepted by NAD+. So, NAD+ is reduced into NADH. The substances that accept electrons during chemical reactions and are reduced to oxidize the other substances are called oxidizing agents. NAD+ serves as an oxidizing agent as it accepts electrons to oxidize malate into oxaloacetate.
D is the correct answer i think.