Fix typo

Author: rizkyzhang

2-ui/1-document/03-dom-navigation/3-navigation-links-which-null/solution.md

@@ -1,5 +1,5 @@
 1. Yes, true. The element `elem.lastChild` is always the last one, it has no `nextSibling`.
-2. No, wrong, because `elem.children[0]` is the first child *among elements*. But there may exist non-element nodes before it. So `previousSibling` may be a text node. Also, if there are no children, then trying to access `elem.children[0]`
+2. No, wrong, because `elem.children[0]` is the first child *among elements*. But there may exist non-element nodes before it. So `previousSibling` may be a text node.
 
 Please note: for both cases if there are no children, then there will be an error.