Plant communities assemble themselves flexibly， and their structure depends on the particular history of the area. Ecologists use the term “succession” to refer to the changes that happen in plant communities and ecosystems over time. The first community in a succession is called a pioneer community， while the long-lived community at the end of succession is called a climax community. Pioneer and successional plant communities are said to change over periods from 1 to 500 years. These changes—in plant numbers and the mix of species—are cumulative. Climax communities themselves change but over periods of time greater than about 500 years.
According to paragraph 1， which of the following is NOT true of climax communities
A. They occur at the end of a succession.
B. They last longer than any other type of community.
C. The numbers of plants in them and the mix of species do not change
D. They remain stable for at least 500 years at a time.
這個題大家都會選擇用climax communities去定位，但在定位過程中會出現很多問題。首先考生要學會跳躍式定位，即根據文章中特殊的標點符號以及最醒目的詞來搜索我們真正需要的關鍵詞。文中的particular是加了陰影的'，succession是在引號裏面的，都非常醒目，通過看這兩個詞我們會發現它們附近沒有我們需要的東西;再比較突出的就是數字及破折號，在500的上方有a climax community，但它是單數，與題幹關鍵詞不完全匹配，細節題講究的是精確定位，所以我們應該選擇500斜下方的Climax communities，即該段的最後一句話。否定事實細節題的出題思路有兩種：一是無中生有，即根據定位點的內容，四個選項只有一個沒有提到，這種思路多適用於選項比較簡短的題目;二是張冠李戴，即根據定位點的內容表述，只有一個選項與之矛盾，這種思路多適應於選項比較長的題目。就這個例題而言，根據定位的最後一句話，從表述上來說跟它相關的只有C和D兩個選項，D項的意思與原句相符，而C項與原句矛盾，所以正確答案是C。
