摘要
Most of the earth is covered with water. About 70 per cent of the water on earth is in the oceans,but water also exists in rivers and lakes. It occurs as ice or water vapour in the air. All together, there are about 330 million cubic (立方体的) miles of water on earth.
出处
《中学生英语（高中版）》
2000年第8期15-15,共1页
English Journal for Middle School Students
