Sam’s been doing his homework since 8: 00, _____

试题详情及答案解析: Sam’s been doing his homework since 8: 00, ______ he?
A. isn’t B. doesn’t C. hasn’t; 答案：C; 试题分析：句意：萨姆从8点就一直做作业，是吗？此题的’s是has的缩写。结合句意，故选C
考点：考查反义疑问句的用法。