题目

If their marketing plans succeed, they ____ their sales by 20 percent.   A. will increase  B. have been increasing  C. have increased  D. would be increasing   答案：A句意: 如果他们的营销计划成功, 他们的销售额将会提高20%。根据句意, if从句用一般现在时表将来, 主句用将来时。  若关于的不等式的解集恰好是，则的值为（    ） A．            B．               C．             D．