2．表示某动作从过去开始发生，持续到现在，并且还有可能持续下去。常用的时间状语有today,
this week, these days, so far, up to now, since, ever since, since
then, by this time, for years / ages, for a long time, several times, in / over
the past few years, “since + 过去某一时刻”,“for + 时间段”等。有时在时间或条件状语从句中，可用现在完成时代替将来完成时。
[考例]Hearing that she __the entrance
exam to the university，Fudy is thrilled．[青岛市]
A．has failed in B.
is succeeded in C．is failed in D．has
succeed in
[答案]D。[解析]本题考查词义辨析 由“听说他成功地通过了考试，Judy非常兴奋。”可知选D。
--It's raining! When did it start?
一I
don't know exactly．In fact，it _________all this afternoon. [北京市]
A1asts B
has 1asted C．1asted D．will 1ast
[答案]B．[解析]考查现在完成时态。从句意“事实上，已持续了整整一个下午了”，不难看出，不能用一般过去时，此句中last"持续”作延续性动词。从信息"all this afternoon"可知。
--Are you
going to see the film with us?
--No,
thanks. I _________ it. [广东省]
A.
saw
B.
have seen C.
see
D.
was seeing
[答案]B．[解析]本题考查动词的时态。由对话的语境可推测句意“我已看过这部电影”，表示过去发生的动作对现在造成的影响或结果，故应用现在完成时。
--Hello,
this is Lily speaking. Could I
speak to Mr. Black?
--Sorry.
He _________ the Xuanwu Lake Park. [南京市]
A. has
been to B.
went to
C.
has gone to D.
will go to
[答案]C．[解析] 考查现在完成时态。have gone to(到某地去了，还没有回来)；have
been to(去过某地，已经回来了)。
Jane _________. I'm waiting for her. [成都市]
A. came
back B. has
come back C.
hasn't come back
[答案]C．[解析]考查现在完成时态。根据后句句意：“我正在等她”可知。