Earth Day is celebration of life and our planet. It is a reminder that we need to ________the world we live in and that we should learn to respect life and nature.
By the end of this year, we _____ 2000 English words.
_______ knows the truth will tell you about it , I think .
The head engineer is in ________ the project .
______ began our new lesson.
I didn’t manage to do it _____ you had explained how.