In our class, when the bell rang and the
问题:
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
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