The mother kept a watch over the sick child all night.母亲整夜照顾生病的孩子.They kept a careful watch over the vineyard throughout the growing season.在整个生长季节,他们都认真地守着葡萄园.The guards were originally hired to watch over the houses as...
Thousands of meteorites penetrate Earth's atmosphere and fall harmlessly to the ground each year.每年,几千块陨石穿过地球大气,掉到地面上,并不会造成什么伤害.One theory about the existence of extraterrestrial life rests on the presence of carbon...