It should be possible, these days, to collect all knowledge you need from the
internet.*
English is a prerequisite. If you haven't mastered it yet, learn it. You
must be able to read, write, speak and understand English, but you don't
have to be perfect here. The lousy English used in this text is mine. That's
enough. All publications are in English. Note the importance of being able to
write in English. Sooner or later you will wish to publish your results.
People must be able to read and understand your stuff.
French, German, Spanish and Italian may be useful too, but they are not at
all necessary. They are nowhere near the foundations of our sky-scraper, so
don't worry. You do need the Greek alphabet. Greek letters are used a lot.
Learn their names, otherwise you make a fool of yourself when giving an oral
presentation.
If you have managed to read and follow this webpage so far, you probably
don't need a first course in English. However, you want to be precise in your
academic publications. You never want to be misunderstood, after all.
* Problem then is, there is so much junk on the internet.
摘錄（一小段）完畢