Вопрос по английскому языку:

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 didnt's want the others to hear him .
7) Don't worry , I'm not ____________ of my mind : I'm simply trying to be realistic .
8) Our new achievements seem to be a good occasion ___________ celebration .
9) Parents are always rewarded ___________ their children'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 .