Backyard gardens seems a bit broad whereas the rest focus in on a certain subject relating to gardens.
Explanation:
Format is the organizational structure of a text. An author might alter the format of a literary work to highlight the differences between things, especially when he or she is trying to deliver information about the contrasts between different situations, characters, or other aspects of the work.
When you preview something, you inspect it. Previewing helps you get a glimpse of what's ahead before you read or something, kind of like skimming.
Dashes because it is within a sentence and it says include a example
In this selection, the sentence seems to be using "the wind was our friend on the way back, though." as an indication that the wind might most likely not nearly as bad as it was when they started to go for a skate. Short explanation: It wasn't as bad as when they first started.
