I failed PSMIII last time with 74 scrore, who has better advice&suggestion?

Since you are the one doing the work for your accreditation, you are in the best position to inspect and adapt based upon whatever feedback you may have obtained. No-one else is. They aren't doing the work and no-one else has the feedback you mighr have received.

I can tell you that this is a fundamental of agile practice which will be explored in increasingly greater depth throughout each assessment.

I can say that (during my attempt) the feedback received did not feel to be written directly for me, but rather generated via some sort of tool. Based on that I can understand the potential root of this question. As a foreigner, I can say that one of the biggest challenges is to read, understood, and write an answer in English in a limited time. I am not a particularly fast writer in my native language, nor in English - so during my preparation, one of my routines was to improve on that by using online tools for fast typing. Another tip may be that as it is tempting to go to the next question without answering one (and returning later), it is rather a bad tactic - just focus on writing the best possible answer and move on - even if it is one sentence. That way you will have more comfort that at least you don't have blanks, and you be able to maintain focus on the question at hand.

As a foreigner, I can say that one of the biggest challenges is to read, understood, and write an answer in English in a limited time.

As a native English speaker, I confirm and confess that this is also true. I found it hard just to type quickly enough. I remember pressing the submit button on PSMIII about 1.5 seconds before the final pip, and it was touch-and-go whether my response to the last question would register at all, or be swallowed up by network latency. Others I know have similar stories to tell.

PSM III is not an exam for the verbose.

You need to hit the salient points and move on to the next question fairly quickly. Like Ian, I was running the clock when I did it. 

For what it is worth, I tried to go with a multi-pass approach meaning I answered succinctly on first pass and added or adjusted in subsequent passes. I tried not to get too hung up on tougher questions though I will admit that was not easy to do. Hard to make up for any lost time so some discipline here could help. 

A few tips:

• Diligently track your time as you go through the assessment.
• Carefully read each question to make sure your answer covers each point being asked.
• Look for question marks within the question to help you determine if multiple points are
  being asked. If there are three questions, make sure to provide at least 3 answers.
• Begin with providing short answers to the questions being asked. Don’t waste time with
  supporting text unless it’s helping to answer the question.
• You have to really know your information and recall it quickly, 2-3 sentences and move
  to the next question.
• Use Professional Scrum terms (e.g. Daily Scrum, not Standup)
• Create several writing prompts on topics such as events, scrum values, empiricism, accountability, artifacts, etc., and practice writing your answers. Don't worry too much about grammar or spelling
• A rigorous understanding of Scrum is essential, almost to the point that your response becomes automatic, and is constrained more by the speed of your typing than your speed of reasoning.

Taking a PSM I and PSM II course is also advised.

I have a tip to non-english speakers like me.

Read (good) books in english

This might be obvious or irreevant, but it is not. I readed many books to prepare to the PSM III and PSPO III. It helped me a lot to improve my vocabulary and to have the right words for the right answers, fast and accurately. 

Keep in mind that PSM III is a spontaneity test as well, that is, it tests whether you have the right answers on the tip of your tongue. Most of time, real life challenges require you to take fast desicions, or at least, give fast answers. People will not let you take some time to think or to do some googling. So, you MUST have the right anwers just in time. And, that's why PSM III is the best cert on agile world, in my opinion. 

Blog posts are good as well. But, remember, good vocabulary > good books, good books > good vocabulary. 

Some fundamental books to get prepared:

• Gunther Verheyen - Scrum Pocket Guide
• Lyssa Adkins - Coaching Agile Teams
• Stephanie Ockerman / Simon Reindl - Mastering Professional Scrum: A Practitioners Guide to Overcoming Challenges and Maximizing the Benefits of Agility

Absorve and apply the right vocabulary

While reading (good) books, keep in mind that the right vocabulary is fundamental. Most languages like portuguese (in my case) have different words for same ideas when comparing to English. A good example is "accountable" and "responsible": those words have the exact same meaning in portuguese, but, represent similar but not the same concepts in English. So, take notes on the vocabulary and force yourself to use them. Understand the differences and applications in english. Scrum Guide is a good source for that, as well. 

Ask yourself good questions

Imagine youself in a TV show, like SNL with David Latterman, being interviewed. Imagine David asking you: "What is empiricism and give a real life experience.". Mentally answer it in 3 minutes. Repeat this until you have a good (and confident) answer. Than, think about other common and related questions. Than, train the same questions and anwers on the keyboard, typing. 

Don't waste your time during the exam

Don't ever fix typos. Keep going and typing. 

Don't try to be perfect. You are not and nobody is. 

The goal on preparation: train your brain (and your fingers) to be objective and clear. 

"PSM III is not an exam for the verbose."

That's priceless and true.  It's also stated in a non-verbose way!  Awesome.