Where does a fertilized egg spend the majority of its time '

Majority of time a fertilized egg spend in the uterus.

Explanation:

Fertilization occurs after 14 days in the fallopian tube outside the ovary.

Fallopian tube links ovary to the uterus.

When the fertilized egg reach down the fallopian tube, then it implants in the uterus.

And an embryo starts growing for approximately 36-38 weeks.

Most of the time, the fertilized egg spend in the uterus.

Hence, uterus is the correct answer.

when a reversible reaction is occurring in both directions at the same rate; the products and reactants do not change in concentration. a chemical reaction where the compound is broken into its constituent parts.

carbon atoms, hydrogen, oxygen, and nitrogen.