Ensuring an adequate water supply have been a concern ever since people began to

游客2023-12-04 60

问题 Ensuring an adequate water supply have been a concern ever since people began to live in towns and cities.

选项

答案 have—has

解析译文：自从人们开始居住在城镇和都市以来，保障足够的水供给一直是个引人关注的问题。
分析：考查主谓一致。主语为动名词短语时，谓语动词应为单数形式，have应改为has。

转载请注明原文地址:http://tihaiku.com/zcyy/3243548.html

相关试题推荐

随机试题

最新回复(0)

Whatisthefirstthingpeopleshouldrememberiftheywanttomakeagoodprese