．—______ I lock the lab before I go home?—Don’t bother．I’ll check it myself later．

Not until he failed in the last examination _________he should have spent more time on study.

Everything he _____ to his country.

In my dream, I had a very vivid picture of ____ we used to live.

The strong wind keeps making the window close by itself. Why not use a rolled-up newspaper to _____ it open