.As reported in the essay by Prof. Brown, it is only in the most difficult circumstances ________ a man’s abilities are fully tested.
Come earlier, ___ you won’t get anything to eat.
Jim said that he would not mind__.
Many black children died ___ cold and hunger in Africa.
His English is very poor.He can’t make himself ___.
16.Nobody knows who is the first one to add fertilizer ___ the soil to make plants grow better.