diff --git a/pages/总复习2023t1.md b/pages/总复习2023t1.md
index 06724df..6bc2e48 100644
--- a/pages/总复习2023t1.md
+++ b/pages/总复习2023t1.md
@@ -2790,7 +2790,10 @@
 			  CLOCK: [2023-06-03 Sat 21:07:06]--[2023-06-03 Sat 21:07:07] =>  00:00:01
 			  CLOCK: [2023-06-03 Sat 21:07:17]--[2023-06-03 Sat 21:07:18] =>  00:00:01
 			  :END:
-			- LATER Binomial coefficient
+			- NOW [binomial coefficient](https://en.wikipedia.org/wiki/Binomial_coefficient)
+			  :LOGBOOK:
+			  CLOCK: [2023-06-16 Fri 21:18:12]
+			  :END:
 			- LATER 写题（作业，对答案）
 			- LATER 总复习, 考试6.19，杰克6.8
 				- LATER 看完网课和串讲 [[Jun 17th, 2023]]