企源知识库

Every means ______ since then.
A、has been trying
B、have been trying
C、have been tried
D、has been tried
【正确答案】：D
【题目解析】：every means意为“每种方法”，谓语动词要用单数，因此可排除选项B和C，方法与尝试之间是被动的关系，所以要用被动语态。