In our class, when the bell rang and the teacher closed his book, it was a ______ for everyone to stand up.
A. signal B. chance
C. mark D. measure
Carbon dioxide, which makes a ________ between us and the sun, prevents heat from getting out of the atmosphere easily, so the earth is becoming warmer.
A．difference B．comparison
C．connection D．barrier
With inspiration from other food cultures, American food culture can take a ________ for the better.
A．share B．chance
C．turn D．lead
I bought a dress for only 2010 dollars in a sale;it was a real.
A. exchange B. bargain
C. trade D. business
The young man made a ______to his parents thathe would try to earn his own living after graduation.
A.prediction B.promise
C.plan D.contribution
While she was in Paris，she developed a________ for fine art.
A. way B. relation
C. taste D. habit
