Look at that tall building!—It is _______tallest building in the city.

It’s seven o’clock. My familybreakfast.

The farmer was very thankful to the doctor _________ saved his son．

To save the drowning child, the boy plunged into the icy water without hesitation, ____ his own safety.

The CD-Rom helps you learn English_________ your knowledge of English grammar and vocabulary.[ ]