Question

Solo necesito ayuda en la B)

Answer 1

Copias el principio de cada oracion y luego agregas 
Because= porque
El verbo HAS/ HAVE( con I , You , They y We) luego el verbo en past participle 
Ejemplo= I know him, because i have met him before.

Answer 2

1- Because he has hurt his leg.2- Because I have lost the key.3- Because I have seen the film.4- Because I haven't put a stamp on it.5- Because he has eaten too much.6- Because they haven't saved money.7- Because I have met him before.