Mary doesn’t do her homework _______,so she always makes a lot of mistakes.
.I don’t remember _______ the book yesterday.
_______ useful information it is!
She is a _______ girl and she always says to her teachers _______.
.The math problem is _______ hard for me ______ work out.
----How do you learn English, Toby ? ---I often practice English _____ talking _____ my American friends.