3.Not until the dedication of Yellowstone Park in the late nineteenth century ____ a national park.
问题描述：
3.Not until the dedication of Yellowstone Park in the late nineteenth century ____ a national park.
(A) the United States had\x0b(B) did the United States have\x0b(C) when the United States had\x0b(D) the United States having
答
b正确.当Not until位于句首时,句子要倒装.其结构为:Not until+从句/表时间的词+助动词+(主句)主语+谓语+.如:①Not until the teacher came in did the students stop talking.直到老师进来学生们才停止讲话.②Not un...