Here is the completed text with the correct word choices:
**Text:**
Do you have any friends (a) **who** can speak nine languages? I do! Alex is a guy (b) **whom** I met in Greece last summer. We were at the language school in Athens (c) **where** we were studying. We were both in a class with a teacher (d) **whose** classes were fantastic. Alex learnt French at school, and then he went travelling round the world and learnt Russian, Polish, Arabic and Japanese (e) **which** made him learn so many languages. (f) **When** he was young, he was taught English, German and Italian.
**Correct choices:**
a) who
b) whom
c) where
d) whose
e) which
f) when