facultative的音標(biāo)是[?f?klt?t?v]，基本翻譯是“任意性的，可選擇的”。速記技巧可以是將其拆分為fac（做）和ult（極限）兩個(gè)詞根，表示可以做也可以不做的意思。

facultative的詞源：

詞根facul（力量，能力）和后綴-tey（表示行為或狀態(tài)）結(jié)合，表示“可選擇的”。

變化形式：

-ly（副詞后綴）

-ative（形容詞后綴，表示主動(dòng)的或具有傾向性的）

相關(guān)單詞：

1. facultative alliance（選擇性的聯(lián)盟）：指可以選擇建立或保持的聯(lián)盟關(guān)系。

2. facultative partner（可選擇合作伙伴）：指可以選擇的合作伙伴，不一定是固定的。

3. facultative language（可選語(yǔ)言）：指可以選擇學(xué)習(xí)或使用的語(yǔ)言，與母語(yǔ)不同。

4. facultative member（可選擇成員）：指可以自愿加入或退出的組織或團(tuán)體成員。

5. facultative contract（可選擇合同）：指可以選擇是否執(zhí)行的合同，具有靈活性。

6. facultative relationship（可選擇關(guān)系）：指可以選擇建立或保持的關(guān)系，可以是友情、愛(ài)情或其他類型的親密關(guān)系。

7. facultative student（可選擇學(xué)生）：指可以選擇是否參加某個(gè)課程或項(xiàng)目的學(xué)生。

8. facultative faculty（可選能力）：指可以選擇具備或通過(guò)學(xué)習(xí)獲得的能力或技能。

9. facultative partnering（可選伙伴關(guān)系）：指可以選擇與某人建立伙伴關(guān)系，而不是婚姻關(guān)系。

10. facultative status（可選地位）：指可以選擇的立場(chǎng)、身份或地位，具有靈活性和多樣性。

常用短語(yǔ)：

1. facultative association

2. facultative symbiosis

3. facultative mutualism

4. facultative monogamy

5. facultative sociality

6. facultative polyandry

7. facultative isolation

例句：

1. Some plants have the ability to form facultative associations with fungi or bacteria.

2. These animals engage in facultative mutualism with other species, sharing resources and protecting each other from predators.

3. Facultative polyandry allows female animals to increase their genetic diversity and potentially their fitness.

4. Some plants have evolved facultative sociality to enhance their defense against predators and competitors.

5. Facultative isolation can be a strategy for individuals to avoid competition and enhance their chances of survival.

6. These organisms need to maintain a balance between facultative polyandry and self-preservation, which is not always easy to achieve.

英文小作文：

The concept of facultative behavior is one that is constantly evolving in our understanding of the natural world. It refers to behaviors that are not obligatory but can be chosen by individuals based on their own needs and circumstances. This flexibility allows for a wide range of adaptations that can be advantageous or disadvantageous depending on the specific situation.

For instance, facultative polyandry refers to the practice of having more than one partner in a given time period, which can provide females with additional genetic benefits, but also comes with risks such as increased predation or competition for resources. On the other hand, facultative isolation can be a strategy for individuals to avoid competition and enhance their chances of survival, but it also requires the ability to quickly adapt to new environments and challenges.

In conclusion, facultative behavior is a fundamental aspect of survival and adaptation that requires constant adjustment and flexibility in response to changing environments and challenges. Understanding this concept is crucial for understanding the adaptations and strategies of organisms in their natural environments and can provide valuable insights into how they have evolved and adapted over time.