I think          important for us to learn a foreign language well.　　

---How many children have you got ? ---Two , _______ of them are studying in the university.

— _______ does Tom like math? —Because _____ fun.

 – Which of the two coats will you take? – I will take ________. One is for my brother and the other is for myself.

 -- Did you read a book about customs last week?-- Yes, I found ______ very useful to know the customs of foreign countries.