It has always been discussed about the influence luck can have on human occurrences. Certainly, it can completely change somebody's life; take for instance lotteries and competitions. But I do not think that in order to advance in position in a certain field, one should rely exclusively on fate. Indeed, fortune can help or thwart somebody, but one will advance his/her career equally if he/she relies on persistence, hard work, sacrifice and effort.
There are many reasons which support this statement. One of the most important arguments is that luck is never always good or always hard; therefore, relying completely on it is useless if not harmful. Luck is inconstant and flighty; the only way to exploit or face it is to employ your skills and abilities derived from persistent exercise and hard work in order to sway the outcome in your favor.
An example of a great career derived from one's merit is the one of Barack Obama. Indeed, he has managed to work his way up to the top despite his many hurdles with hard work and persistence.
Besides, one who bases his position only on luck will have more difficulties than those who base his career on their own merits. In condition of bad luck, the worthy person will overcome troubles using his/her own skills, whereas the lucky one will be swept away. It follows that success derived from fortune is greatly more temporary than the one derived from one's merit. For example, students who study constantly and periodically will be eased in the difficulties, while inconstant students will be obstructed.
Another point against the reliance on fortune is that the goals that one has earned thanks to good luck are considered less prestigious that those which have been reached through hard work.
Moreover, good luck can be also a disadvantage. A major part of our experience is made up of failures. If one does not fail, that is he/she is particularly lucky, he/she will be unprepared to the negative future shifts of fate.
In conclusion, a great career does not depend mainly on fortune. It is true that it can be eased or impeded, but the major part of one's position depends on one's merit and skills.

Twitter is better than Facebook
Social network have been spreading uninterruptedly in these years. The most popular is still Facebook, but others are emerging from the rest. This is the case of Twitter, which lately has become more and more attended. Most of the great personalities have got both a Twitter and a Facebook profile. Many people even think it is better than its counterpart Facebook. I agree with these latter for some reasons.
First of all, Twitter is used for different purposes from the ones of Facebook. On Facebook people speak mainly about their everyday life, what they are doing at the moment and what they are going to do. They rarely chat about a specific or serious topic. On the contrary, on their Twitter profile they put only necessary information about a certain theme, idea, work or project.
This aspect is further supported by the 140-character limit of Twitter. Indeed, the shortness of the messages compels you to have something to say in order to draw the attention of the followers.
Afterwards, Twitter lets you select better information. On Facebook you come across all the news, photos and videos that your friends put in their profile; in this way, you are informed also about topics in which you are not interested but your friends are. On the contrary, Twitter keeps you up to date only about narrow and selected topics, depending on which person you have chosen to follow.
One point in favour of Twitter is that it is faster and quicker than its counterpart. News, events and thoughts are indeed synthesized in 140 characters. For the same reason, it helps also improve one's ability to summarize and consequently one's control of the language.
For all the previous reasons, Twitter is also better than Facebook for study purposes, because it is less flighty and dispersive.
However, Twitter too presents some drawbacks. Firstly, Twitter's utility depends greatly on how it is used and which people you choose to follow. Like all tools, it can be used both to help and to harm. After that, the 140-type limit can accustom you too much to immediacy. Last but not least, all tweets are always public and sharable by everybody.
Considered as a whole, I think that Twitter is more useful, serious and pointed than Facebook. Anyway, I cannot make a more precise comparison between them because I have neither a Facebook profile nor a Twitter one.