---Do you have trouble finishing the work? ---The work is not so difficult as you think.We have finished it already.
Americans eat __ vegetables per person today as they did in 1910.
I wonder if you know it ___ .
The number of people invited ___ fifty, but a few of them ___ absent for different reasons.
—George is a wise person. —But in my opinion, he is ___ than wise.
The roof fell ____ he had time to rush out.