- What does the professor main discuss?
- A. ways that stars become nebulae
- B. reasons that nebulae appear to give off blue light
- C. difference between nebulae and stars
- D. a basis for classifying types of nebulae
2. What point does the professor make about orion’s sword?
- A. it points toward a nebula in the constellation taurus.
- B. it contains a nebula that looks like a star to the naked eye.
- C. it contain stars whose light is a reflection of other nearby stars.
- D. it contains two stars that are remnants of a supernova.
3. What does the professor say about the origin of the crab nebula?
- A. It was formed when interstellar gas clouds combined.
- B. It was created by an exploding star.
- C. It did not emit when it was first formed.
- D. It was formed in the same way as many reflection nebulae.
4. Based on the lecture, which answer choices describe emission nebulae and which describe reflection nebulae?
[Click on an answer choice, Then drag in to the space where it belongs. One of The answer choices will not be used.]
|emission nebulae||Drag your answer choices here|
|reflection nebulae||Drag your answer choices here|
- A. They give off red light.
- B. They give off blue light.
- C. They can only be seen from locations near the equator.
- D. They do not contain glowing gas.
5. What is a typical characteristic of dark nebulae?
- A. They are obscured from view by nearby stars.
- B. They are located in parts of the sky that do not contain bright stars.
- C. The dust and gas they contain are too dense to let light through.
- D. They are too hot to emit radiation in the visible range.
6. Listen again to part of the lecture. Then answer the question.
Why does the professor say this: 🎧
[So star formation is not necessarily the source of the light in Emission Nebulae.]
- A. To clarify his previous statement
- B. To call attention to an unusual phenomenon
- C. To emphasize a feature of all types of nebulae
- D. To repeat a point he made earlier
答案：D B B A&BD C D