How to use "lowest" in a sentence

Sentences

The time I woke up after the operation was the lowest point after my escape

The law was bad, they said - the lowest age for boys to marry was eighteen, but the lowest age for girls was sixteen.

Now, the lowest age to get married in Zimbabwe is eighteen, and it's the same for boys and girls

In Guatemala and Malawi, for example, the lowest age for marriage is now higher