Please help, I've been stuck on this question for a while. Can anyone explain it?

Which traits do human embryos have that link them to a common ancestor with fish and reptiles? a. scales and tail b. gill slits and scales c. tail and gill slits d. hair and tail

This drawing shows a human body system. what is the primary function of this body system?

Acandle’s wick is the fabric string that holds the flame, and it burns down at a constant slow pace when the candle is lit. the wick is usually surrounded by wax. which is the most important property of covalent compounds that makes them useful for making candle wax? a low boiling point a low melting point a high boiling point a high melting point