______ professional violinist practises for several hours a day , but ______ violinist has his own way of playing the Beethoven concert . 

This is such a letter ____came last night．

---What major will you choose when you are at university?---____ but English, which has brought terrible dreams to me for the past 12 years. 

__________ the reason , research shows that laughter is good for your health.

It was hard for him to fit in a new class, in which ______ he was familiar with.