a week ago 和since last week 的区别

a week ago 和since last week 的区别 he has been away from the factory .a a week ago b since a week ago He has been away from the factory ---------.A.a week ago B.since a week ago C.for a week ago a week ago和last week有什么区别? susan arrived here a week 空格,and has been here ever 空格.a.befor;ago b.befor;since c.ago;befor d.ago;since 选一个 I borrowed a book from the library a week ago.=A week _______ ______ since I borrowed the book I bought the dictionary a week ago(改为同义句) I ____ _____the dictionary _______a week ago.答案是have ,had,since,结构是I have had(现在完成时)+since+a week ago(一般过去时)吗? Tom has had a dictionary since last week ago哪错了 It has been snowing since a week ago.(改为一般疑问句) They arrived here . A．since a week ago B．a week ago C．for a week D．next weekThey arrived here . A．since a week ago B．a week ago C．for a week He told us he____ a concert_____.A.had atteneded ;three days beforeB.attended;a week agoC.would attend;since a week ago D.was atteneding;for a week 两个句子判断正误The poor old man has died for a week.The poor old man has died since a week ago.是（错, I haven't heard from him last week.I haven't heard from him _____ last week.(A)since (B) for (C)ago (D)before They__(make) a kite a week ago. 1 We have been here since ten years ago.------------------------2 I borrowed a book a week ago.------------------------------------3 The boy bought the computer two years ago.----------------------------------------------4 He has been in beijing for Ago ,since 和 for 有什么去别呀? His father left Shanghai a week ago.(for a week) he has kept a car since one year ago（对since one year ago 提问）