Write a detailed overview of Atticus and describe at least two struggles faced by him?A character sketch would be perfect, ...

Atticus, as a character, is a bit of a Southern anomaly for this time period -- that is, he is broad-minded, intellectual, objective, and incredibly just in all of his dealings, even with his children. In this way, he is well ahead of his time mentally speaking.

One struggle he faces is that of being a single father. Having to raise tomboyish Scout and her brother Jem in a time that was marked by the stereotypical nuclear family is a trial in and of itself. With no wife present, Atticus is left to play the role of both mother and father, with a great deal of help from Calpurnia, who serves as maid, cook, and mother-figure for the Finch children.

The second struggle that Atticus faces comes in the form of community perception. Prior to Atticus agreeing to defend Tom Robinson, he was thought of as a pillar of the Maycomb County community -- an unequivocable voice of fairness and reason as an attorney, and a member in good standing of the town itself. When Atticus agrees to defend Tom Robinson, his reputation and his community standing are both brought into question, and furthermore, are greatly disparaged. This disparagement by his neighbors, friends, and society at large comprises Atticus's second struggle as a character. 

What can you infer about the historical and cultural context of "The Crucible"?What do these people believe and fear and how do they see the world?

The village Salem in the 17th century was a theocracy (no separation of church and state), so spiritual reputation was an important status symbol.  Salem made not distinctions between public and private affairs, so what was going on behind closed doors or in even a person's "soul" was a matter of public record.  The village was, of course, male dominated, so women (especially foreign, non-Christian) and children were meant to be seen and not heard.  The church preached the concepts of total depravity (man's soul is born sinful), predestination (God knows who's going to heaven before they're born) and the unconditional election (only a select few could enter into heaven).  What's more, the church stressed that the devil was loose on the earth and in competition for souls, so evil was a real force.

In The Crucible, Arthur Miller wanted to parallel the religious mass hysteria from the Salem Witch Trials with the pandemonium of the Red Scare McCarthyism of the 1940s and 1950s.  So, you can substitute "communist" for the "devil" or "witch," and the results will be about the same.

What are the theme, dilemma and catastrophe in "The Drunkard"?

The dilemma in "The Drunkard" is how to keep Mick Delaney from getting drunk at the public house following the funeral of his friend and confidante Mr. Dooley. Frank O'Connor structures the story so that an extremely emotional and compelling event virtually inescapably drives Mick, who has a problem with drunkenness, to the public house. The thought of Mick in the public house and the inevitable consequences for Mick distress his wife to the extreme causing her to reach for extreme measures to fend off the inevitable.

So in hopes of resolving the dilemma of Mick needing to be at his friend's funeral followed up by an emotional stop at the public house, she sends their son with him to try to help him keep the "brakes" on his drinking. The catastrophe, of course, is that Larry becomes drunk himself. The theme is the irresponsibility and horrendous of the habitual drunkard, whether the drunkard him/herself or a boy imitating the drunkard.

What led to the hike in gasoline prices in the late 1970s?

Since the Iranian Revolution occurred during the Carter administration and the OAPEC oil embargo occurred during the Nixon administration, the reason for the gasoline price hikes cannot be attributed to the Iranian Revolution which had not yet taken place.

The greatest shortages took place in the early 1970s, so, therefore, the revolution of 1979 cannot be the cause.  Part of the cause of OAPEC's embargo in 1973 was the US support of Israel; the Arabic nations sought to punish the United States for resupplying the Israel military. This conflict was termed the "Yom Kippur War" when oil jumped from $3.00 per barrel in 1972 to over $12.00 per barrel in 1974.

By 1974 Secretary Kissinger negotiated an Israeli troop withdrawal from parts of Sinai.  This promise of a negotiated settlement between Israel and Syria prompted the Arabic nations to lift the embargo in March of 1974.

As a result of the America's dependency upon foreign oil, a move was made after this AOPEC embargo for production of American oil as well as provision for oil reserves.  (e.g. The National Oil Reserves)

At the end of the novel, Atticus reads to Scout. Comment on his choice of story.And does it have any connection with themes earlier in the novel...

I agree with the previous poster. I'd like to add, too, that the ending of the novel brings the reader full circle. Before her first day of school, when her teacher had told her not to let her father read with her anymore because it would cause "damage" to her learning, Scout often spent time with her father and a book. At the novel's end she's also wearing overalls again. Contrary to what many people have said about Scout's development in the novel, I believe that she hasn't transformed fully into a young woman or "lady." If you view the ending as a repetition or revisiting of the beginning of the novel, Atticus' choice of reading material makes sense. The Gray Ghost is one of Dill's books (from the beginning of the novel) that he brought with him on his summer visit, right?

Update: I checked the opening chapter and it looks to me like Dill brings the copy of The Gray Ghost with him from Meridian. Two passages in Chapter 1 make me think this: Scout tell us that "Dill bet Jem The Gray Ghost against two Tom Swifts..." and Dill says to Jem: "I'll swap you The Gray Ghost if you just go up and touch the house."

Describe three differences between DNA (Deoxyribonucleic Acid) and RNA (Ribonucleic Acid).

First of all, there are structural differences. This is reflected in the part of the name that refers to the sugar/carbohydrate. RNA contains ribose, while DNA contains deoxyribose, a similar sugar that contains one fewer oxygen molecule (de...oxy). Another difference is that DNA is double-stranded, while RNA is a single strand. Three of the nitrogenous bases are the same in the two types (adenine, cytosine, and guanine), but DNA contains thymine while RNA contains uracil.

There are also functional differences. DNA is the blueprint for all proteins formed by the cells. mRNA takes the message to the cytoplasm, to rRNA, where tRNA brings the amino acids to string together into polypeptides--in the order that was originally dictated by the DNA

Why Coriolanus is a tragic character?

Coriolanus is a tragic hero because he meets all the criteria.

First, he is a man of elevated birth.  He comes from one of the finest families in Rome.  He proves himself as a hero and savior of Rome in his battles against the Volscian.

Like many tragic heroes before him, Coriolanus is guilty of hubris.  His pride will not let him "lower" himself.  He considers himself better than the plebeians who question him.

His excessive pride leads him to abandon Rome and his family and join the Volsci.

Once he turns his back on Rome, he is doomed.  That he must die in the end is a foregone conclusion.

In the end, it is his pride that causes his downfall and that makes him a tragic hero.