The sentences that should be edited for parallel structure usage are:
-
Jeremy waited for the bus, decided to walk instead, and on his walk, he ran across an old friend.
- This sentence mixes different structures ("waited," "decided," and "on his walk, he ran across") and should be revised for parallelism.
-
Hiking is great for exercising, getting fresh air, and to make connections with nature.
- Here, "exercising" and "getting" are gerunds, while "to make" is an infinitive, creating a lack of parallel structure.
The other sentences maintain parallel structure correctly.