What are the keywords in the following sentence? A bridge rises to let two ships pass.
bridge, let, pass

What are the keywords in the following sentence? realistic falling snowflakes seamless pattern .
fall, pattern, snowflake

What are the keywords in the following sentence? A white clock says it's one minute to six.
clock, minute, say

What are the keywords in the following sentence? an advertisement adorns the since demolished building outside structure .
building, demolish, structure