It seems that water from this tap ________ for some time.We'll have to take it apart to put it right.
A．had leaked B．is leaking
C．leaked D．has been leaking
—I hear Jane has gone to the Holy Island for her holiday.
—Oh，how nice！Do you know when she ________？
A．was leaving B．had left
C．has left D．left
The discussion ________ alive when an interesting topic was brought in.
A．was coming B．had come
C．has come D．came
My mind wasn't on what he was saying，so I'm afraid I ________ half of it.
A．was missing B．had missed
C．will miss D．missed
All the preparations for the task ________，and we're ready to start.
A．completed B．complete
C．had been completed D．have been completed
Selecting a mobile phone for personal use is not an easy task because technology ________ so rapidly.
A．is changing B．has changed
C．will have changed D．will change
