What are combinations that always go together?

Question

for example:salt and pepper- ying and yang- and stuff like that...if you could help that would be wonderful...thank you!

Answer 1

Funerals and mourners.

Bars and alcohol.

Flags and flagpoles.

Oceans and salt.

Lawns and lawnmowers.

Swimming pools and water.

Carousels and music.

Zoos and animals.

Prisons and prisoners.

Prisons and guards.

Guns and bullets.

Gardens and gardeners.

Rockets and rocket launchers.

Fireworks and matches/lighters.

Firetrucks and ladders.

Construction sites and dirt.

Farms and farmers.

Schools and students/teachers.

Books and pages.

Pen and ink.

Rainforests and rain.

Mountains and altitude.

...you should be able to find a couple of suitable ones there...

Answer 2

Birds and bees

Answer 3

ketchup & mustard,  

Answer 4

peanut butter and jelly, peas and carrots, his and hers, paper or plastic...

Answer 5

well, I hate to be picky but it's "yin" and "yang"

anyway. . . how about

Peanut Butter and Jelly,

hot and cold,

right and wrong,

good and bad,

lost and found,

day and night,

left and right,

up and down,

in and out,

on and off,