The Use of Articles (a, an, the)

One of my pitfalls in English grammars is misusing of articles. Articles, including a, an, the, sometimes is quite confusing to me. Furthermore, such a pitfall occurs easily especially when I focus on the content of one sentence or the structure of it. Anyway, I am careless, and misusing of articles occurs often. After I studied using of articles through Internet, I found using them correctly is actually challenging.
The articles are divided into two categories. One is definite articles, including “the”. The other is indefinite articles, including “a” and “an”. Literally, when we use “the”, we refer to a specific or particular thing. When we use “a” or “an”, we refer to a general case or thing. For example, I just saw the most popular film in this year, which means I just saw that particular film. In the contrast, I would like to see a film, and here a film refers to any film.
As to the differences between “a” and “an”, “a” begins with an initial constant sound, while “an” begins with an initial vowel sound. An initial vowel sound does not refer to an initial letter of the adjacent word. For example, we use “a European country” instead of “an European country”. In addition we must distinguish count and noncount nouns, and we do not add “a” or “an” before a noncount noun even we want to refer to a general case.
As to the use of “the”, we should note its geographical use. We do not use “the” before names of most countries and territories, names of streets, names of lakes, bays, mountains. However, we should use “the” before names of rivers, seas, oceans, names of desserts, forests, gulfs, peninsulas, geographical areas and points on the globe.
I need to apply the rules listed above to avoid misusing of articles in the later academic writing.

Energy: a grand challenge for Engineering

Recently petrol’s price is increasing sharply, and this draws people’s great attention to petrol and its substitutes. However, for engineers and scientists, energy problems have been a long and great concern since the end of 20th century. For the following 21st century, engineers and scientists will need to do more to meet increasing demands with limited fossil resource. This essay will focus on the limitation of fossil resource, the technology of improving the efficiency and the bright prospect of new resources.
As we all know, the fossil resource, including petrol and coal, is limited. Firstly, it usually takes millions of years to form such resources from the bodies of dead animals and plants. Thus, it is almost impossible to have more fossil resource within the survival of human beings. Secondly, for thousands of years, our main energy comes from the fossil resource. Especially for hundreds of years after industrial revolution, the consuming speed is greater and greater. As a result, the fossil resource left is very limited.
Faced with limited fossil resource, we need to improve the efficiency of using it to get the maximum energy. For example, we can convert solid coal into powder to burn more efficiently and gain more energy. Another example is mixing petrol with alcohol, which is wide spread in some parts of China, and feedback is quite good.
Because of limited fossil resource and increasing demands, we have to develop new resources. Among new resources, sunshine and nuclear fusion are accessible and popular. We can get huge energy from these two resources, if we find proper and efficient ways to make full use of them. Certainly, it is we engineers’ duty to accomplish it. Besides great energy, these two resources are clean, which means they do not generate any toxic gas, liquid or solid.
In conclusion, as engineers, we will shoulder the duty of improving efficiency of using resources and developing new resources. To achieve this target, we should study and work hard from undergraduate studies.