It is no use trying to talk him into studying hard; he can only be by force.
Jack is the right person you can rely on to ____ the research when you are on vacation for the next two weeks.
He failed the final examination and only then ____ how much time he had wasted.
Recently, however, scientists have been finding that long-term use of these fertilizers can cause damage to the land, thus _____it less fertile.
When the area was _______ by the flood, the government organized people to send food and medicine there immediately.
People should ______the traffic rules when they travel to a new place. Nobody can be exception.