The expansion of desert like conditions into areas where they did not previously exist is called desertification.

问题描述:

The expansion of desert like conditions into areas where they did not previously exist is called desertification.

(The expansion主语 of desert like conditions (定语修饰The expansion)into areas(也是定语修饰The expansion )where they did not previously exist(定语从句修饰areas )is called 谓语desertification.主语补足语
desert like应为desert- like中间应有连线号,desert- like做定语修饰conditions 意思是象沙漠一样的环境,整句意思是象沙漠一样的环境扩展到原先没有沙漠的地方称之为沙漠化
你买的可能是盗版书,质量有问题.

the expansion...previously exist这是主语从句,is是谓语。

主要结构:The expansion of desert (主) is called desertification.沙漠的扩张就叫做沙漠化.like conditions into areas where they did not previously exist 此为插入语.like是指The expansion of desert (主...