fix typo in Inline Fragments section (graphql#152)

Author: AndreiRailean

site/learn/Learn-Queries.md

@@ -254,7 +254,7 @@ query HeroForEpisode($ep: Episode!) {
 
 In this query, the `hero` field returns the type `Character`, which might be either a `Human` or a `Droid` depending on the `episode` argument. In the direct selection, you can only ask for fields that exist on the `Character` interface, such as `name`.
 
-To ask for a field on the concrete type, you need to use an _inline fragment_ with a type condition. Because the first fragment is labeled as `... on Droid`, the `primaryFunction` field will only be executed if the `Character` returned from `hero` is of the `Droid` type. Similarly for the `homePlanet` field for the `Human` type.
+To ask for a field on the concrete type, you need to use an _inline fragment_ with a type condition. Because the first fragment is labeled as `... on Droid`, the `primaryFunction` field will only be executed if the `Character` returned from `hero` is of the `Droid` type. Similarly for the `height` field for the `Human` type.
 
 Named fragments can also be used in the same way, since a named fragment always has a type attached.