Помогите пожалуйста очень безотлагательно . Use the prepositions from the box

Помогите пожалуйста очень срочно . Use the prepositions from the box to complete the sentences . Предлоги : about , at , by , for , in , of , out . 1) If you change your mind ________ joining us , please , let us know . 2) There are certain matters that can be discussed only ___________ private . 3) Do you think children should be rewarded ____________ good marks or good behaviour ? 4) Some teachers call their pupils _____________ their second names , but others prefer to use first names . 5) Some people prefer ro lie __________ their age . 6) He spoke ___________whispers as he didnt39;s want the others to hear him . 7) Don39;t worry , I39;m not ____________ of my mind : I39;m simply trying to be realistic . 8) Our new achievements seem to be a good occasion ___________ celebration . 9) Parents are always rewarded ___________ their children39;s achievements and their love and care . 10) Have you heard your name called ___________ ? 11) White I was out of the classroom , somebody typed a funny poem _________ my computer .