Stand-alone Possessive pronouns

Are these beautiful paintings________.

• yours
• your

I think that this skateboard is ______.

• his
• its

I do not know what I want for______ birthday.

• my
• mine

This is _____ and that is ________.

• hers, your
• hers, yours
• her, your
• her yours

I took _____ blankets back in the morning.

• their
• their 

I will watch your dog if you watch _____.

• my
• mine