three-quarters of the time怎么翻译啊?

three-quarters of the time怎么翻译啊? three quarters of the mountain__with trees three quarters of the earth is water three-quarters of an three quarters of the students能否说成three quarters students Three quarters of the population of our country are farmers the ocean covers three quarters of the earths surface ,produ in the first three quarters of the year Three quarters of the city was destroyed in the war three quarters of the staff作主语,谓语动词用单数还是复数啊? 9.Three quarters of the earth _________ water.(discover) Three quarters of the earth___(be) covered with water.