C~~~~~~~~解释下老师我不懂怎麼解释诶～只能给你几个例子：These colours are caused by what is known as interference of light. 这些颜色是由所谓的光的干涉产生的.The United States has what is usually described as a capitalist economy. 美国实行的经济制度通常被称为资本主义经济.