The 5-week-old human embryo has external gill slits (grooves). they do not develop into gills, so what happens to them?

As the gills does not develop into gills, they are likely to contribute to the development of the lower jaw of the human embryo though after the embryonic stage, the gill slits won’t be retained or won’t be a part of a human as they only appear during embryonic stage for the development of the lower jaw.

slitherio is the original. its the best friend of all middle schoolers. the man you can count any time you have some free time. slitherio is the guy you hang with while you're in the computer lab suppose to be doing "research or whatever". slitherio isn't just a game but a friend.

wormaxio is just a fake trying to squeeze its way into the friend group. trying to pretend its cool and your best pal but how long has it really been there for you, really. it only wants you as friend to boost its social status. wormaxio is just annoying fake pleb. no offense

you and have a wonderful day

hydrogen is a compound or a single element and a element is a pure substence that cannot be separated into simpler subtances

clorine is a compound its a chemical substance that forms when two or more different elements combine

so both hydrogen and clorine are compounds