1. What do the following words have in common?

CUR
FUSE
SENT
CEDE
SCIENCE
DESCEND

2. What do the following words have in common?

TON
POSE
LONG
GRAM
PORTION
POSITION

HINTS:
1. Each word can be preceded by the same three-letter word.
2. Each word can be preceded by the same three-letter word.

Answers:

1. Each word can be preceded by CON.
2. Each word can be preceded by PRO.