Student or Learner
could you please tell me which prepositions are correct:
1) This item is intended for the sole use of/by the authorized person.
2) It is designed for use of/by the company.
3) These items may not be left in/on/at places without adequate security.
4) These items may not be left in/on/at other premises without adequate protection.
Thanks a lot!
the correction respectively are by, at, at