The university estimates that living expenses for international students around $8,450 a year,which a burden for some of them. A.are; is B.are; are C.is; are D.is; is 答案:A。考查主谓一致。句意:这所大学估计一名国际生的生活开销每年大约是8 450美元,这对其中的一些学生来说是一大负担。living expenses生活开销,为复数名词,故谓语动词用复数;$8,450为金钱概念,谓语动词用单数。如图所示,用A、B两把刻度尺测同一物体长度,B刻度尺的分度值是2mm2mm.图中放置正确的是AA刻度尺,该物体的长度为2.202.20cm.