diff --git a/src/pages/p/2019/08/句子1.1.md b/src/pages/p/2019/08/句子1.1.md
index 97bb553..f2f5322 100644
--- a/src/pages/p/2019/08/句子1.1.md
+++ b/src/pages/p/2019/08/句子1.1.md
@@ -9,3 +9,5 @@ tags:
 ### Sentence quiz
 
 Please see [`slide:github:patarapolw/zhdiary/slides/句子1.1.md`](slide:github:patarapolw/zhdiary/slides/句子1.1.md)
+
+Highlight text and press "x" inside the presentation to speak.
diff --git a/src/pages/p/2019/08/句子1.2.md b/src/pages/p/2019/08/句子1.2.md
index c8f87d9..7d6e897 100644
--- a/src/pages/p/2019/08/句子1.2.md
+++ b/src/pages/p/2019/08/句子1.2.md
@@ -9,3 +9,5 @@ tags:
 ### Sentence quiz
 
 Please see [`slide:github:patarapolw/zhdiary/slides/句子1.2.md`](slide:github:patarapolw/zhdiary/slides/句子1.2.md)
+
+Highlight text and press "x" inside the presentation to speak.