Complete the sentences with the suitable infinitives: to understand, to fly, to read, to know, to buy, to see.

This is the film __.
Who was the first man __ into space?-Y.Gagarin was.
This is the money __ the dictionary you need.

This is the film to see. Who was the first man to fly into space? - Y. Gagarin was. This is the money to buy the dictionary you need.