In the last twenty or thirty years, however, the use of coal (63) _______ declined. As a result, there have been changes in the coal industryĐoạn văn55/97In the last twenty or thirty years, however, the use of coal (63) _______ declined. As a result, there have been changes in the coal industryhavewas is hasGiải thíchChọn đáp án D