With inspiration from other food cultures, American food culture can take a ______ for the better.
Our maths teacher set so difficult an examination problem ______ none of us worked out.
This is the second factory, ______ I used to work, many workers of______ still have a good relationship with me.
It’s impossible for him to escape ______ this time; he made such a big mistake.
The ______ look on the student’s face suggested that your ______ question made him ______.
Only ______ as an interpreter ______ how important it was to grasp English.