Barack Obama has taken personal blame ________ the security failures which led ________ the attempt to blow up a plane on Christmas Day. A. of; to B. for; to C. on; on D. in; on 答案:B下图是某厂2005年各季度产值统计图,则下列说法正确的是( )A. 四个季度中,每季度生产总值有增有减B. 四个季度中,前三季度生产总值增长较快C. 四个季度中,各季度的生产总值变化一样D. 第四季度生产总值增长最快