In our class,when the bell rang and the teacher closed his book,it was a ________for everyone to stand up.
The world is _______ seven continents and four oceans.
It is difficult for you to ______ what will happen in space without gravity.
Since we have met again after all these years, let's____ each other from now on.
She was given the chance to ______ designing the new bridge.
The line is engaged. I can't _____ now.