________in the heart of Toronto is the Canadian National Tower , which is often called the CN Tower for short.
21.The moment we heard the news of the earthquake, we began to ________ the work to rescue those who were trapped in the building.
20. When Jane began to take swimming lessons, her main__________was the fear of water.
19. The language used in advertisements differs from____________used in ordinary readings.
18._________is often the case, he didn’t study hard and failed to pass the test.
17.They had a pleasant chat____________a cup of coffee.