$\text { 9. Cô ấy là bạn của anh ấy. }$
$\text { +) She is his friend. }$
$\text { -) She isn't his friend. }$
$\text { ?) Is she his friend? }$
$\text { 10. Họ là những người anh trai của cô ấy. }$
$\text { +) They are her brothers. }$
$\text { -) They aren't her brothers. }$
$\text { ?) Are they her brothers? }$