Question

read the passage. there are several questions about this passage.
stinkiest place—the rotten egg of io
1 what makes a place stinky? it is quite subjective, really. many scientists believe that smells warn us of potentially harmful chemicals—bad smells indicate things that are bad for us (although this theory does not explain why humans eat liver and onions). however, many things stinky to humans are beneficial to other living things. rats inhabit putrid trash bins, some bacteria eat methane, and flies like poop. so, we have taken a distinctly human perspective to determine the stinkiest place in the solar system. it’s really no contest—jupiter’s moon io produces the biggest stink of all.
2 this is not to say that the solar system lacks stinky places. earth has its fair share—boggy marshes, geothermal areas, landfills, and pig sties, to name a few. new zealand’s 55 million sheep and cattle produce about 90% of the country’s methane emissions (kiwi farmers have fervently opposed a “fartulence” tax). indonesia is home to the exotic and popular durian, a fruit with such an offensive odor that it is banned in singapore hotels and subways. on venus, corrosive clouds of sulfuric acid completely envelop the planet, producing an acid funk of global proportions. hydrocarbons on saturn’s moon titan fall as toxic precipitation, pool in lakes and streams on the surface, and seep into the underlying goopy soil. titan smells like one big oil refinery.
3 but jupiter’s moon io smells like a jumbo rotten egg, and the stinky compound has been observed both on its surface and in the upper atmosphere. in fact, the sheer abundance of sulfur compounds creates the moon’s distinctive red and yellow coloration.
4 during explosive volcanic eruptions—spectacular events that are quite common on io—sulfur gases launch high into the atmosphere. although the mechanism is not completely understood, photochemistry decomposes some of this sulfur gas and forms sulfur dioxide, hydrogen sulfide, and other sulfuric compounds. sulfur molecules freeze on the surface to form red patches near volcano vents. eventually, the red frost on the surface turns yellow as sulfur molecules react to form stable sulfur rings.
this question has two parts. answer part a, and then answer part b.
part a
how does paragraph 8 mainly contribute to the development of the ideas in the passage?

1. it explains how scientists obtained information about io.
2. it compares old volcanic activity on io to more recent activity.
3. it gives reasons that the volcanic activity on io is extraordinary.
4. it provides evidence that the orbit of io is unlikely to change.

part b
select two excerpts from paragraph 8 that best support the correct answer from part a.

1. “gaseous burps emanate”
2. “over 400 active volcanic pores”
3. “ever-changing surface”
4. “sulfur plumes extending as high as 300 km”
5. “biggest volcanic eruptions on earth”

Explanation:

Part A

To solve Part A, we analyze each option:

• Option 1: The paragraph doesn't focus on how scientists obtained info about Io. Eliminate.
• Option 2: It's not about comparing old and recent volcanic activity. Eliminate.
• Option 3: Paragraph 8 (from context, likely describing Io's volcanic activity) gives reasons why Io's volcanic activity is extraordinary (like active pores, sulfur plumes, etc.). This fits.
• Option 4: The paragraph doesn't discuss Io's orbit change. Eliminate.

We need to find excerpts from paragraph 8 that support the idea that Io's volcanic activity is extraordinary.

• Excerpt 1: "Gaseous burps emanate" – doesn't strongly show extraordinariness. Eliminate.
• Excerpt 2: "over 400 active volcanic pores" – a large number of active pores shows extraordinary volcanic activity. Keep.
• Excerpt 3: "ever - changing surface" – shows dynamic nature due to volcanoes, supports extraordinariness. Keep.
• Excerpt 4: "sulfur plumes extending as high as 300 km" – high - reaching plumes show extraordinary activity. Keep? Wait, but the question says "select two". Wait, maybe I misread. Wait, the correct answer for Part A is that it gives reasons Io's volcanic activity is extraordinary. So excerpts that show the extent of volcanic activity:

"over 400 active volcanic pores" (shows many active volcanoes) and "sulfur plumes extending as high as 300 km" (shows large - scale volcanic plumes) or "ever - changing surface" (shows continuous change due to volcanoes). Wait, let's re - evaluate.
Wait, the options:

1. "Gaseous burps emanate" – too vague.
2. "over 400 active volcanic pores" – number of active pores is a reason for extraordinariness.
3. "ever - changing surface" – result of volcanic activity, shows it's dynamic.
4. "sulfur plumes extending as high as 300 km" – height of plumes shows scale.
5. "biggest volcanic eruptions on Earth" – compares to Earth, but the focus is Io's own activity.

To support "volcanic activity on Io is extraordinary", the best two are "over 400 active volcanic pores" (option 2) and "sulfur plumes extending as high as 300 km" (option 4) or "ever - changing surface" (option 3). Wait, maybe the intended answers are option 2 and option 4 (or 2 and 3). Let's check again.

If Part A's answer is that it gives reasons Io's volcanic activity is extraordinary, then:

• "over 400 active volcanic pores" – shows a large number of active volcanoes, which is extraordinary.
• "sulfur plumes extending as high as 300 km" – shows the scale of volcanic activity, which is extraordinary.

Or "ever - changing surface" – shows that the surface is constantly changed by volcanoes, which is extraordinary.

But let's assume the correct two are option 2 and option 4 (or 2 and 3). Let's go with option 2 ("over 400 active volcanic pores") and option 4 ("sulfur plumes extending as high as 300 km") as they directly relate to the scale and extent of Io's volcanic activity, supporting its extraordinariness.

Answer:

1. It gives reasons that the volcanic activity on Io is extraordinary.

Part B