It was difficult to guess what her________to the news would be.

________ have an internal clock that controls the beating of our heart, and the ________ of our breathing.

He thought this was the first pair of shoes that had fitted him ________.

I think you should go back to your     plan, which is much more practical than the present one.

---Do you work in this office?---No, as a clerk in this office is on vacation, I’m just ____ here for about a week.