The question is incomplete, the complete question is found in the image attached.
Answer:
1- acceptor
2-donor
3-acceptor
4-donor
Explanation:
A hydrogen bond acceptor is a molecule that has an electronegative atom having a lone pair of electrons that participates in the hydrogen bond.
A hydrogen bond donor is the molecule that supplies the hydrogen atom of a hydrogen bond.
If we look at structure I-IV in the image attached, I and III are hydrogen bond acceptors because they all possess electronegative atoms having lone pairs of electrons but do not have hydrgen atoms bonded to highly electronegative atoms.
Similarly, structures II and IV are hydrogen bond donors. The C=C double bond is electron withdrawing and highly electronegative making the hydrogen atoms attached to it acidic and hydrogen bond donors. Also, nitrogen is an electronegative atom thereby making structure IV a hydrogen bond donor.
