One in twenty people have an extra rib.
Twenty is an integer. Not sure what you mean with "in humans".
The twenty-three chromosomes in humans is called a haploid number. It refers to the number of chromosomes in a gamete of an organism.
28"21" but to be extra smart the answer is "The seventh triangular number is twenty one."
yes
Humans have twenty deciduous teeth.
Down syndrome occurs when an individual receives an extra 21st chromosome.
Yes, extra nipples are very common. Depending on the place where the study was done, the incidence can range from one in two hundred to one in twenty people.
one hundred twenty-eight
121 is one twenty-one
One in particular was mastering EVA (Extra Vehicular Activity). He proved that humans can work in space.
humans have 26 of these rods, a crossword with 10 spaces, 2nd H 10th is e
one thousand twenty and twenty-five hundredths is written 1,020.25