If you are not familiar ____ the topic, you may write something that is familiar ____ you.
Sorry, I am late. I ______ have turn off the alarm clock and gone back to sleep again.
___________ was most important to her, she told me, was her family.
The man _______ the little boy and said , “You are so clever and lovely . I love you very much.”
________ work has been done to improve the people’s living standard.
He made another wonderful discovery , ____ of great importance to science.