What is the ruling on preparing food for someone who is not fasting in Ramadan?
It is forbidden to prepare food for someone who is breaking their fast without a valid excuse in Ramadan.
Doing so would be assisting in sin, and assisting in sin is itself a sin.
Allah says {what means}: "but help ye not one another in sin and rancour" [Al-Mai`dah/2]
What is the ruling of Islamic Law on speaking with one's fiancée (before the marriage contract) by telephone and WhatsApp?
All praise is due to Allah, and peace and blessings be upon our master, the Messenger of Allah.
Before the marriage contract, the two engaged persons remain non-mahram (strangers) to one another. Reciting al-Fātiḥah, receiving some money on account of the dowry (mahr), or accepting a gift are all merely a promise of marriage and not a valid contract under the Sharīʿah.
It is therefore forbidden for the engaged couple, before the marriage contract is concluded, to be alone together (khalwah) or to shake hands. It is likewise forbidden to speak by telephone or correspond without need. And Allah Almighty knows best.
Should nail polish be removed before making ablution?
Yes, it should be removed because it prevents water from reaching the nails.
Is an animal that results from crossbreeding between two types of livestock (an'ām) valid [for sacrifice]?
Praise be to Allah, and peace and blessings upon our master, the Messenger of Allah.
An animal that results from crossbreeding between two types of livestock (an'ām) is valid [for sacrifice], with consideration given to the higher of the two required ages. Thus, in the case of an animal crossbred between sheep (ḍa'n) and goats (ma'z), only one that has reached two years of age is valid [for sacrifice]. And Allah, the Most High, knows best.