confusion question

The earliest Mayan pottery found at Colha, in Belize, is about 3,000 years old. Recently, however, 4,500-year-oold stone agricultural implements were unearthed at colha. These implements resemble Mayan stone implements of a much later period, also found at Colha. Moreover, the implements’ designs are strikingly different from the designs of stone implements produced by other cultures known to have inhabited the area in prehistoric times. Therefore, there were surely Mayan settlements in Colha 4,500 years ago.

Just saw your comments on what I wrote at random, in fact I have yet no idea about GMAT.

Before I say something about your question, I would straightforward say that your English is probably good enough but it seems your thought of CR could be on the wrong way.

I could, however, still explain simply the question by understanding the language itself: Does choice D support the final concusion"Therefore, there were surely Mayan settlements in Colha 4,500 years ago."? On the contrary, it weakens. Think about it once more! I don't compare choice D with others whether it is the most but definitely it weakens the above mentioned conclusion.

You pointed out the correct choice and I explain it accordingly, which shows off nothing.  I would not like to be misunderstood therefore.

As to the above explanation, sorry, I do not get it, since you seemed not to expound it. If you don't hope to get misunderstand once more, please put your ideas in detail.

Well, to illustrate the point from a diffirent angle but same expression constructure, I take the follows as a example.

"You speak the same English language as what American speak, therefore, you are from America."

Then,I give two more sentences here for you to judge whether the second sentence weakens a/m conclusion.

"Moreover, residents outside America speak different languages from English as their mother tongues."

"People living elsewhere speak English on the grounds that understanding the most powerful people in the world is of great importance for them."

Above mentioned point is the same as the original question and I would be delighted on conditions that you understand what I endeavor to expound.

In fact, I yet have no idea about how to answer GMAT questions even though I have met two CRITICAL REASONING questions and got to know GMAT briefly by surfing the Internet which has been helpful for me to prepare IELTS exam significantly. Just ten days ago when I finished my IELTS exam (21st - 22nd January, 2006) for imigration to Canada and my university classmate (long time ago - I graduated from Tsinghua University 16 years ago), who's enjoying his MBA study in UBC, Canada, suggested me to sit the GMAT exam, I started to see what about GMAT. However, I found somebody explained a CR question extremely mysteriously and abstrusely - LZ knows which question it is and he does not agree with me - and at random, I wrote my opinion to solve the problem by simply understanding the language itself and using my natural critical reasoning ability without being trained at all.

Why I wrote is just to say personally that we could be confused to be on the wrong way by too complicated teaching and explaining - I had the same problem for preparation IELTS but fortunately I got back.

You should never ever do the same as what others do, in contrast, you are better off finding out what is your most suitable way as it is the best.