—You've made great progress in your studies of English, haven't you?—Yes, but much________to be done.
He will keep ________ new ideas so he can help farmers around China.
It is difficult for us to achieve success ______ we’ve actually changed the situation.
Some poems tell a story or describe something in a way ______ will give the reader a strong impression.
I do hope so because I want you to live ________ as I have.
English is not easy _____.