This is a synonym relationship. 'Authentic' means the same as 'Genuine', just as 'Bogus' means the same as 'Fake'.
Mend : Break :: Unite : ?
💡 Explanation
This is an antonym relationship. 'Mend' is the opposite of 'Break', just as 'Unite' is the opposite of 'Separate'.
Keyboard : Computer :: Rudder : ?
💡 Explanation
This is a part-to-whole relationship. A 'Keyboard' is a part used to direct a 'Computer', just as a 'Rudder' is a part used to steer a 'Ship'.
Trowel : Mason :: Awl : ?
💡 Explanation
This is a tool-to-worker relationship. A 'Trowel' is a tool used by a 'Mason', just as an 'Awl' (a pointed tool for piercing holes) is used by a 'Cobbler'.
Seed : Plant :: Egg : ?
💡 Explanation
This is a cause-and-effect (or origin-to-result) relationship. A 'Seed' grows into a 'Plant', just as an 'Egg' hatches into a 'Bird'.
Tranquil : Calm :: Tumultuous : ?
💡 Explanation
This is a synonym relationship. 'Tranquil' is a synonym for 'Calm', just as 'Tumultuous' is a synonym for 'Chaotic'.
Frugal : Extravagant :: Humble : ?
💡 Explanation
This is an antonym relationship. 'Frugal' (thrifty) is the opposite of 'Extravagant' (wasteful), just as 'Humble' is the opposite of 'Arrogant'.
Verse : Poem :: Act : ?
💡 Explanation
This is a part-to-whole relationship. A 'Verse' is a constituent part of a 'Poem', just as an 'Act' is a constituent part of a 'Play'.
Abacus : Accountant :: Sextant : ?
💡 Explanation
This is a tool-to-worker relationship. An 'Abacus' is a calculating tool used by an 'Accountant', just as a 'Sextant' is a navigational tool used by a 'Navigator'.
Friction : Heat :: Cloud : ?
💡 Explanation
This is a cause-and-effect relationship. 'Friction' is a cause that produces the effect of 'Heat', just as a 'Cloud' is a cause that produces the effect of 'Rain'.