What do these 3 words have in common
100

Bird, Dog, Tree

What is house.

birdhouse,doghouse,treehouse

200

List, mail, out

What is black

Blacklist, blackmail,blackout

300

Dial, flower, room

What is sun.

Sundial,sunflower,sunroom.

400

Log, spin, breaker.

What is back,

backlog,backspin,backbreaker

500

Birth, math, image.

What is after.

Afterbirth,Aftermath,Afterimage.