Strictly speaking knowledge is immense, but not infinite, as it is the result of Mankind's intellect, acting over a long but not infinite amount of time (history, or prehistory plus history). The unsolved questions or unknown things might be infinite, and if they are infinite they will always remain infinite, as Mankind (always a huge but finite aggregation of men and women) could only turn finite amounts of those questions into knowledge; of course the right questions should also be raised, before conquering anything. Another possibility could be the discovery of general formulas and relations by which : a) producing questions b) producing the answer related to a question via a finite collection of algorithms In this manner we could theoretically list any (finite) amount of questions and automatically produce the answers; I believe this possibility has been explored by the great English mathematician Alan Turing (who by the way gave a significant contribution also in defeating the Nazis in WWII) and the result is that it is impossible (I'm not sure if I'm reporting the result correctly). Also Godel gave important tributes to this kind of questions.

由于知识的多样性和无限性，即使我们穷极一生的时间，也无法完全肯定自己能够成为某一领域的专家，就更不用说成为多领域的专家了。

Oops... I guess I've just mistaken your question...

I think Since knowledge is diverse and infinite, it is uncertain whether we can become an expert of only one domain or not, even if we spend our lifetime on it, not to mention several domains.

I think Since knowledge is diverse and infinite, it is uncertain whether we can become an expert of only one domain or not, even if we spend our lifetime on it, not to mention several domains.