Applying Letter Phrases

Dear Sir or Madam,

I am interested in applying for the job of helper with the …. Project, advertised in the… on 11 May.
I am writing to apply for the position of … advertised in…. on May 12.
My reasons for wishing to join the team are that I have always been interested by… and I would very much like to … my knowledge of … by doing … of this kind.
My reasons for applying are that I have always been interested in working in the…industry
I would like to develop my knowledge of…, and I enjoy communicating a foreign languages.
And during the school holidays I used to (what relevant experience do you have)
Last year I was student at (which school?)…