Prince William took a visit to the Forbidden City on Feb. 28, ______ emperors once lived.
The _____ look on his face suggested that the teacher was quite _____ with the result.
______, I came to realize that my parents could not always stand by me.
In my opinion, more attention should be ______ the environment, which is of great importance.
I owe my success to Mr. Smith, a teacher from America, ______ help I have greatly improved my oral English.
Many species are in ______ danger of extinction now due to the foolish actions of ______ human race.