The students found it easy to_______ what the experienced teacher had taught.
Feathers fall to the ground slowly,________ stones fall much faster.
The children are seldom encouraged ________up late at night preparing their lessons,if ________.
Though great efforts have been ________on her study,Annie can’t still make any improvements,which makes her parents greatly________.
The population of the city ________from less than half a million in 1949 to over two million.
—I’m going to the office. —________ you’re there,can you get me some stamps?