--The light in the office is still on.

--Oh, I forgot ________.

[　　]

--You were brave enough to raise objections at the meeting.

--Well, now I regret ________ that.

[　　]

--Are your through with your homework?

--No, in fact I _______ .

[　　]

A. have just started

B. just started

C. am just starting

D. have just been starting

Our school is different from _______ it used to be.

[　　]

No matter _______ he tried, he couldn't develop a new plant.

[　　]

It is connected with the use the body _______ energy.

[　　]

Was it during the Second World War _______ he died?

[　　]

It was about 600 years ago _______ the first clock with a face and an hour hand was made.

[　　]

Beyond _______ stars, the astronauts saw nothing but ______ space.

[　　]

These new facts, together with what you have heard, _______ that he is honest.

[　　]