This "it" generally represents an animal or an object. If it is used to refer to boys, it is his, and girls are hers, so before using it, you must know what you are referring to, people or things.
/iknow-pic . cdn . BCE Bos . com/500 FD 9 F9 d 72 a 605960292 b 152434349 b 033 BBA 80 " target = " _ blank " title = " " class = " ikqb _ img _ alink " >； /iknow-pic . cdn . BCE Bos . com/500 FD 9 F9 d 72 a 605960292 b 152434349 b 033 BBA 80？ x-BCE-process = image % 2f resize % 2Cm _ lfit % 2Cw _ 600% 2Ch _ 800% 2c limit _ 1% 2f quality % 2Cq _ 85% 2f format % 2Cf _ auto " esrc = "/ 500 FD 9 F9 d 72 a 605960292 b 152434349 b 033 BBA 80 "/>
There are many such abbreviations in English, which are just for convenience and have no other special meaning. They have the same meaning as not abbreviations, such as: are not = arenot.