вставьте артикль (а/аn/the) Там где он нужен 
1 .... Sir W Churchill was .... famous politician .
2 ..... Ivanovs are our friends .
3 My brother is .... lawyer 
4 .... Masha lives in .... Sovetskay Street  in an Saratov
5 .... Volga is the longest river in the Russian Federation