Have you ever wondered how a microwave oven works? It's amazing, really. You feel like having a snack right away, so you microwave a bag of popcorn. In less than two minutes, your snack is ready. What could be easier or quicker?
If your family has a microwave oven, you probably use it every day to cook or reheat food. These ovens can heat foods much more quickly than can regular ovens.
They also use less electricity because they are only heating the food and nothing else. But how is this possible?
The clue is in the word microwave. The "wave" in the word refers to a specific type of invisible radio wave. These electromagnetic waves are the same as those used in cell phones and garage door openers. Water, fats, and sugars in food absorb these waves. Glass and most plastics do not absorb them, and metal reflects them. The waves enter food and "excite" or stimulate the water and fat molecules in the food to start moving faster. The movement creates heat. This in turn excites the other molecules in the food to move more quickly and heat up.
As you can see, there's a lot of excitement going on when you press the start button of a microwave oven!
1. This passage is mainly about.
A. how to cook microwave popcorn.
B. how microwave ovens heat food.
С. how garage door openers work.
D. how a microwave start button works.
2. What causes food in a microwave oven to heat up?
A. being in a glass or plastic container
B. a current of water and electricity
С. being in a metal container
D. the movement of molecules inside the food
3. Based on the passage, a microwave is most convenient when..
A. baking a cake.
B. someone is hungry and does not have much time to cook.
С. getting ready for a large dinner party.
D. preparing cold meals.
4. Which of the following is a fact from the passage?
A. Microwave ovens make tastier food than regular ovens.
B. Microwave ovens come with exciting start buttons.
С. Microwave ovens heat food in less than two minutes.
D. Microwave ovens heat food more quickly than regular ovens.
1. B. how microwave ovens heat food.
2. D. the movement of molecules inside the food
3. B. someone is hungry and does not have much time to cook.
4. D. Microwave ovens heat food more quickly than regular ovens.