It is useful to science _______ the earth as an object in space.

We must ______ that the experiment is controlled as rigidly as possible.

Be careful, _______ you'll fall down.

_______ the movie I would have finished my paper last Sunday.

The boy ran out of the classroom without the teacher's _______.

I'm sorry I forgot to write; I had so much else ________ my mind.

I don't know how we can make ________ on the timetable for any more courses.

________ from the occasional late night party, our neighbors are very quiet.

We were told that Sue would be ideal for the job, but she ________ badly when we talked to her.

________ to the papers is restricted to Defense Department personnel only.