Let’s say a snake entered a boy’s bedroom while the boy is there and police are discussing the situation. Unlike a baby where the child’s gender is not usually immediately obvious, if the police knew he were a boy, they would call him a boy even if he or say two years old.
In English, a baby is a child from the start of his or her life. When he hits his teens, news programs for example will then usually call him a teenager and then from age 20 call him an adult.
Before the teenage years, if the gender of a child is known, CNN for instance will tend to call that child not a child but a boy or a girl.
This is in the tips and notes.
If you are totally new to duo (Or have never seen them before), you'll need the tips and notes,
how to get tips and notes:
organized by skill in one pdf for the whole course: https://www.docdroid.net/JnfmyEV/tipsnotesbackup.pdf
Replace your username where USERNAME is for information on your progress & the tips & notes: https://duome.eu/USERNAME/progress
The whole course tips and notes are here (and the site has one for each Duolingo language): ,organized by skill individually: http://duolingo.wikia.com/wiki/Hebrew
You can also get them on the duolingo.com site (make sure your browser is in desktop view mode so you can see the other duolingo features like discussions & timed practice (the language clubs are only on the app though). From discussions you can search for all the discussions in this course (like this one you're reading, as well as see general duolingo discussions). If you can't see discussions on the main screen once logged into duolingo you're not in desktop view.