diff --git a/notes/MongoDB_聚合.md b/notes/MongoDB_聚合.md
index 3900921..c0a8482 100644
--- a/notes/MongoDB_聚合.md
+++ b/notes/MongoDB_聚合.md
@@ -347,7 +347,7 @@ db.employees.aggregate([
 	]
 },
 
-........
+.........
 
 {
 	"_id" : ObjectId("5d3ffaaa8ba16934ccce99a4"),