29. It is known to us that doing eye exercises ________ our eyes, and that is to say, our eyes can ________ doing eye exercises.
—What a bright room! Is it a classroom? —No, it __________ the students' reading room.
It was a really terrifying experience. Afterwards everybody was very __________.
__________ by the beauty of nature, the couple decided to settle in this area.
Because of his illness, he has to stay at home all day __________ he were a bird shut up in a birdcage.
—Putting on a happy face not only helps us make friends but also makes us feel better. — __________.