One-third of the world’s land surface is desert .（ 划线提问 ） __________ __________ of the worl
问题描述：
One-third of the world’s land surface is desert .（ 划线提问 ） __________ __________ of the worl
One-third of the world’s land surface is desert .（ 划线提问：one-third ）
__________ __________ of the world’s surface is desert
答
What proportion of the world's land surface is desert?