I don’t understand Spanish well so please help with these questions

In spanish, the plural form “my” to changes; mis does not change; mis changes; mi does not change; mi

Which one of the following is a trick used in spanish to identify the right hand? touch the tips of your index fingers with the tips of your thumbs. the hand that forms a lowercase b is your mano derecha. touch the tips of your index fingers with the tips of your thumbs. the hand that forms a lowercase d is your mano izquierda. touch the tips of your index fingers with the tips of your thumbs. the hand that forms a lowercase d is your mano derecha.

Which is a rich source of vitamin c?