the bad news is that a third of the world' s population. that 引导的是什么从句？同位语？

the bad news is that a third of the world' s population is already short of water.

表语从句，陈述主语the bad news 的内容。 再如： The reason why he was late was that he had failed to catch the bus. 请及时采纳，不懂继续问( 天天在线 ）(*^__^*) 祝学习进步! 谢谢！

当主语被most of ,some of ,分数，百分数修饰时后面的谓语的确定要看这些词后面的名词，如果是可数名词就用动词的复数形式，如果是不可数名词就用动词的单数形式，因此本题应该填写is，比如：three quarters  of the earth is covered with water.

twenty percent of the students like learning english.

手工翻译，尊重劳动，欢迎提问，感谢采纳！