根据给定的单词列表生成一篇词汇练习题。
包含一些单词的列表。
以下是一个词汇练习题：
1. What is the definition of "perplex"?
2. Use "ambivalent" in a sentence.
3. What is the synonym for "enormous"?
4. What is the antonym for "altruistic"?
5. What is the meaning of "zeitgeist"?
6. Use "effervescent" in a sentence.
7. Give a synonym for "plethora".
8. What is the antonym for "ephemeral"?
9. What is the definition of "facetious"?
10. Use "cathartic" in a sentence. 

单词列表： perplex, ambivalent, enormous, altruistic, zeitgeist, effervescent, plethora, ephemeral, facetious, cathartic.