diff --git a/题库0.3/BasicKnowledge.json b/题库0.3/BasicKnowledge.json
index 824f7c21..aa37e1a7 100644
--- a/题库0.3/BasicKnowledge.json
+++ b/题库0.3/BasicKnowledge.json
@@ -428,7 +428,7 @@
         "objs": [
             "K0226001B"
         ],
-        "content": "点$P(a,b)$关于直线$l$的对称点的坐标为$P'$\\blank{50}."
+        "content": "点$P(a,b)$关于直线$l:y=x$的对称点的坐标为$P'$\\blank{50}."
     },
     "B00061": {
         "lesson": "K0226",