diff --git a/pages/总复习2023t1.md b/pages/总复习2023t1.md
index 5111911..98f73fa 100644
--- a/pages/总复习2023t1.md
+++ b/pages/总复习2023t1.md
@@ -2275,7 +2275,8 @@
 						- Risks :-> a likelihood that a threat will exploit a vulnerability
 						  and cause harm, where the harm is the impact to
 						  organization, **Risk = vulnerability + threat**
-						- Safeguards
+						- Safeguards :-> safeguard reduces the harm posed by information
+						  security vulnerabilities or threats
 					- Risk management
 	- LATER 概率论 (隔了一个周末)
 	  collapsed:: true