题目内容：

it s only a w___ of time to speak to him.he will never listen to others.

优质解答

答案是：waste
句意：和他说话只不过是浪费时间,他不会听取其他人的.
解析：a waste of time即浪费时间的意思.
only在这里只是加强语气,不属于特殊语法.
补充知识：it's a waste of time to do sth.
意思是做什么事纯属浪费时间（这件事还没有实际发生）.
it's a waste of time doing sth.
意思也是做某事纯属浪费时间（这件事已经做过）.