In the park , the number of the visitors is tightly ____ to avoid damaging the environment or putting stress on the animals.
―Do you know where David is? I couldn’t find him anywhere. ―Well. He ______ have gone far — his coat’s still here.
As a physics teacher, Mr. Chen devoted himself to teaching and researching, which earned him a good ______ in his field.
I hate ________ when someone makes a mess of my learning materials on my desk.
Do you have ________ Smith here? I’d like to have ________word with him.
—Putting on a happy face not only helps us make friends but also makes us feel better. — _______.