Complete the sentences.
To(2), in(2), at(3),by
1) This picture is ... Valentin Serov, my favourite painter.
2) Do you often go ... the theatre ?
3) My good friend and I are interested ... painting.
4) His sister is very good ... drawing.
5) The say there's a new ballet ... this opera house.
6) There's a good collection of puppets ... this museum.
7) The boy made his new picture ... pencil.
8) How important ... you is your hobby ?