He started school the same day as I did and ________ to it like a duck to water.
Getting your students ________ in classroom activities is vitally important.
Mr. Tiger insisted that he _______ the money back to his boss but his boss said that he didn’t receive it.
_______ in the leg made it impossible for him to walk to school every day.
We were stuck at the airport because of the heavy fog, otherwise we ________ here in time for the conference.
—It is said that he is focusing on another book on space exploration. When will it come out? —It is _______ next year.