diff --git a/assets/section_1.2_1686899993390_0.edn b/assets/section_1.2_1686899993390_0.edn
new file mode 100644
index 0000000..d89c87b
--- /dev/null
+++ b/assets/section_1.2_1686899993390_0.edn
@@ -0,0 +1 @@
+{:highlights [], :extra {:page 2}}
diff --git a/assets/section_1.6_1686904326481_0.edn b/assets/section_1.6_1686904326481_0.edn
index 8b9e37a..19fb63b 100644
--- a/assets/section_1.6_1686904326481_0.edn
+++ b/assets/section_1.6_1686904326481_0.edn
@@ -248,4 +248,4 @@
                           :page 27},
                :content {:text "Theorem"},
                :properties {:color "yellow"}}],
- :extra {:page 29}}
+ :extra {:page 30}}
diff --git a/assets/section_2.1_1686906896256_0.pdf b/assets/section_2.1_1686906896256_0.pdf
new file mode 100644
index 0000000..f6daf3a
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diff --git a/assets/section_2.1_1686906920851_0.edn b/assets/section_2.1_1686906920851_0.edn
new file mode 100644
index 0000000..5d9ecfe
--- /dev/null
+++ b/assets/section_2.1_1686906920851_0.edn
@@ -0,0 +1 @@
+{:highlights [], :extra {:page 3}}
diff --git a/assets/section_2.1_1686906920851_0.pdf b/assets/section_2.1_1686906920851_0.pdf
new file mode 100644
index 0000000..f6daf3a
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diff --git a/pages/总复习2023t1.md b/pages/总复习2023t1.md
index 304ad6c..053c731 100644
--- a/pages/总复习2023t1.md
+++ b/pages/总复习2023t1.md
@@ -2612,9 +2612,10 @@
 			  :LOGBOOK:
 			  CLOCK: [2023-06-16 Fri 15:00:23]--[2023-06-16 Fri 15:18:37] =>  00:18:14
 			  :END:
-				- NOW Ch1
+				- DONE Ch1
+				  collapsed:: true
 				  :LOGBOOK:
-				  CLOCK: [2023-06-16 Fri 15:31:10]
+				  CLOCK: [2023-06-16 Fri 15:31:10]--[2023-06-16 Fri 17:15:08] =>  01:43:58
 				  :END:
 					- Experiment, Sample Space and Random Event ![section 1.2.pdf](../assets/section_1.2_1686899993390_0.pdf)
 					- Events as Sets
@@ -2683,7 +2684,12 @@
 						- ((648c206e-8ce7-4a74-9ba5-4991d761909f))
 					- ((648c27ed-e09d-4f1a-8100-7ae2dfff1c8e))
 						- ((648c27f9-f944-4bf8-9e44-cb3e9048d286))
-						-
+					-
+				- NOW Ch2 Random Variable
+				  :LOGBOOK:
+				  CLOCK: [2023-06-16 Fri 17:15:12]
+				  :END:
+					- ![section 2.1.pdf](../assets/section_2.1_1686906920851_0.pdf)
 			- LATER 学积分
 			  :LOGBOOK:
 			  CLOCK: [2023-06-03 Sat 17:05:07]--[2023-06-03 Sat 17:05:08] =>  00:00:01