Answer: They retain their chemical properties
Step-by-step explanation:
Mixture is a substance which has two or more components which do not combine chemically and do not have any fixed ratio in which they are present.
For example: Air is a mixture which consists of various gases, water vapors and various particles in solid form which are not present in any fixed ratio, do not combine chemically and thus retain their chemical properties.
Thus the only true statement about substances in a mixture is that they retain their chemical properties