THE ARTICLE: a - an

Read and complete the sentences with the article " a " or " an " .
( Lee y completa las oraciones con el artículo ? a ? o ? an ? ) .
e . g . My mother has ____ new car .
My mother has a new car .
1 . I have ____________________ old cellphone .
2 . She is ____________________ engineer .
3 . We need ____________________ big house .
4 . He is ____________________ nice friend .
5 . The monkey has ____________________ orange .
6 . You need ____________________ umbrella .
7 . I work at ____________________ big university .
8 . This is ____________________ old hotel .
9 . I want ____________________ hamburger .
10 . She is here in ____________________ hour .