问题
选择题
--Where have you _______ all day?
--- I came back at noon and I _______ in this office since then.
A．been in; had been
B．been in; was
C．been; have been
D．been; am
答案
答案：C
题目分析：句意：你整天都在哪里？我在中午回来了，自从那时后就一直呆在办公室里。句中有since句中用现在完成时，故选C
点评：现在完成时表示动作已经完成，并对现在造成了影响。初中阶段注意两个词所连的时间状语，即for后面加一段时间；since后面加点时间，有这两个短语在句子中时，句子都需要用现在完成时。