Every possible means _______ been taken to prevent the river _________.

A．have; polluting

B．has; polluted

C．has; from being polluted

D．have; being polluted

台湾的社会心理学家黄光国曾指出，发展中国家或地区在学术研究方面的创新探索通常是事倍功半，甚至举步维艰，其根源是缺乏对学术创新领域判断标准的内化与坚持。