II. Read the following text and choose the correct answer to each question.

In 1912, Clarence Birdseye went to live with the Inuit people of the North American Arctic. The Inuit taught him how to fish under the ice. As Birdseye pulled the fish from the water, he put them on the snow and continued fishing. The fish froze almost immediately because of the cold Arctic air.

Birdseye went to eat the fish a few days later. He noticed that they tasted as fresh as the day he caught them. Usually, frozen fish tasted old, and less flavorful. He wondered why the fish tasted better. Maybe it was because of how fast they froze.

Birdseye moved to Massachusetts and began experimenting with freezing food. He developed a new way to freeze it. He blasted the food with air chilled to -43℃. After he developed this method, he founded the General Seafood Corporation. Soon, Birdseye began experimenting with freezing other types of food.

Frozen food was a success! It revolutionized the food industry. Now people could enjoy fresh tasting food at any time of the year. They could even eat food that was packaged far away. Clarence Birdseye has changed the way we eat.

Listen! Someone _________ (knock) on the door.