It was not until 1911, _______ the first vitamin was identified, _______ people realized the importance of it.
_____ English learners, we should not only be able to understand the meanings expressed by the language itself but also ______ expressed by postures, gestures and facial expressions.
Afraid ______ face before his students, the teacher refused ______ that he was in the wrong.
Her acting skills are ______ those of the world famous actress,.
I don’t suppose he is ______ to come to our help when we get into trouble.
“Thanks” is a(n) _______ commonly used to express one’s gratitude to someone for something he has done for you.