Thanks for your comment!

To begin with, thanks to newspapers, people are exposed to a wealth of valuable information. That is to say, prior to the publication of a newspaper, all the news must experience a strict process of verification and censorship, boosting the credibility of most articles. In fact, some long-established papers such as The New York Times or the Guardians are still considered as reliable news sources.

I might rewrite the paragraph like this:

Thanks to newspapers, people are exposed to a wealth of information. Generally, this news goes through a strict process of verification which boosts the credibility of the journalist and the articles. Long-established papers such as the Guardian and The New York Times owe their prestige to the rigor with which they check their information and balance their reporting. Unfortunately, however, there are other papers which do not share this responsibility...(etc)....

The phrase "that is to say" in your paragraph should explain more about the previous sentence (either the wealth of information or the fact that people are exposed to it)

I think in Paragraph 1, you could use "some journalists lack credibility" or even "cannot be trusted." In the conclusion, you could leave "believable" as it is, or change it to "truthful" or "accurate" or "trustworthy"
 

First and foremost, thanks for your help.

I thinked about your comment, and I suppose "truthful" can replace "believable", right?

But I wonder if I omit "that is to say,", whether my essay may be unconnected?? Can you give me some suggestions to link the topic sentence with the supporting sentence?

Thanks for this essy. It's an interesting topic!

• What else could you use instead of the word 'unbelievable' in Para 1 and 'believable' in the last paragraph?
• Would it help if your intro focused on journalists in particular, rather than the media in general?

I like the last part of your thesis sentence. 

In para 2, I'm not happy with the phrase "That is to say." It refers back and should explain more about the previous sentence, which is about how useful papers are, so it's a bit of a non-sequitur (something that doesn't follow logically).

Your example of the NYT or Guardian as reliable sources is good, following the previous sentence correctly.

To begin with, thanks to newspapers, people are exposed to a wealth of valuable information. That is to say, prior to the publication of a newspaper, all the news must experience a strict process of verification and censorship, boosting the credibility of most articles. In fact, some long-established papers such as The New York Times or the Guardians are still considered as reliable news sources.

Your other ideas are well organized and developed.

In the conclusion, I would change a little:

It is high time that both the government and the whole media make concrete efforts to let make sure that all the news are is believable.

 ("news" is singular)

It goes without saying that the media enables people to broaden our command of the world. However, some people hold the belief that journalists are unbelievable. In this essay, I will discuss about trustworthiness of news and offer some crucial qualities of a pressman.

To begin with, thanks to newspapers, people are exposed to a wealth of valuable information. That is to say, prior to the publication of a newspaper, all the news must experience a strict process of verification and censorship, boosting the credibility of most articles. In fact, some long-established papers such as The New York Times or the Guardians are still considered as reliable news sources.

However, in order to fulfill the general expectation of viewers, journalists could invariably disregard their professional ethics. To be specific, in the money-driven world, instead of reporting the truth, unscrupulous journalists often take account to common taste and habit of the majority and then are willing to create colorful, scandalous stories, which aim at better satisfaction of customers and maximizing profit. This, hence, leads to a misperception of the world in readers.

Personally, what can redeem this complicated phenomenon are the necessary qualities of journalists. In other words,if a reporter is able to use exact words and suitable phrases to impart the fact exactly to the public as what happened, it might help to avoid misunderstanding. Furthermore,as a  journalist, they need to be impartial and should possess a sense of strong responsibility for what they write or talk to reflect the truth without any personal emotion and motivation.

To conclude, it is a brazen violation of the people’s basic right when depriving them of knowingthe truth, so it is high time that both the government and the whole media make concrete efforts to let all the news are believable.