It’s high time that we gave ______ attention to our world climate and led a low-carbon life, or the consequence would be too serious for us to face.
He is really an excellent doctor and he is _____ to becoming an expert in this field.
He is such a strong-willed person that there is nothing in the world that can _____ him.
Come and see me whenever ____.
As we can see, the prices of vegetables _____ according to the season.
I felt very tired when I got home. and I _______ straight to bed.