My daughter had a new idea.
After learning a few vocabulary at night, I told my daughter to keep away the book.
MM: Mummy, I will put it next to my bed tonight, then tomorrow I bring it downstair SO THAT the vocabulary will go into my brain when I sleep through wifi.
I know she is just lazy.
I found her actually put the book underneath the pillow and sleep on it!
Oh my...maybe she really think it works.