I read _______ story about Shen Nong. Do you know who he was, Tony—He was_______ emperor in ancient China.

This is my ________ time visit to America. I have never been there before.

The__________ murder to the president astonished the whole country.[ ]

Excuse me. Where is the stair— Ok. Go straight ____that door under the EXIT sign.

Look! A man is cutting a tree on the moon. –It ______be true. The teacher said there is no air on the moon.