Combine each pair of sentences by changing one of the sentences into a participial phrase.Number one: New England rock formations are like some in...

A participle is a verbal that functions as an adjective. 
The verb typically has "ing" added to it to become a verbal.  A participle phrase is
used to modify a noun.

Number
one:

New England rock formations are like some in Britain.
Their similarities intrigue geologists.

Change the verb
"intrigue" into "intriguing".  Now combine the
sentences.

Intriguing geologists with their
similarities, New England rock formations are like some in
Britain.

Number
two:

New foresters learn how to fight forest fires. They
observe fires on film.

Change the verb "observe" into
"observing".  Now combine the sentences.

New
foresters learn how to fight forest fires by observing fires on
film.