feat: examples

ex/theme-04-fruit/practice-04.md

@@ -2,6 +2,8 @@
 
 ### Exercise 10. Complete the word
 
+Example: r e _ -> red
+
 1. p e a _ h
 2. m e l o _
 3. k i w _
@@ -9,6 +11,8 @@
 
 ### Exercise 11. Read and choose
 
+Example: apple / banana -> apple
+
 1. It is small and red. It is a cherry / melon.
 2. It is green inside. It is a kiwi / plum.
 3. It is big. It is a melon / lemon.
@@ -16,6 +20,8 @@
 
 ### Exercise 12. Make a sentence
 
+Example: my / book -> My book.
+
 1. This / kiwi  
    ____________________
 2. These / cherries