In this task, you're given passages that contain mentions of names of people, places, or things. Some of these mentions refer to the same person, place, or thing. Your job is to write questions that evaluate one's understanding of such references. Good questions are expected to link pronouns (she, her, him, his, their, etc.) or other mentions to people, places, or things to which they may refer. Do not ask questions that can be answered correctly without understanding the paragraph or having multiple answers. Avoid questions that do not link phrases referring to the same entity. For each of your questions, the answer should be one or more phrases in the paragraph, and it should be unambiguous.
--------
Question: Passage: The chain of craters has been the subject of several writers and naturalists. Mark Twain visited Mono Basin in the 1860s and wrote about Mono Lake, but did not mention any of the Mono–Inyo Craters except for the lake's two volcanic islands. He wrote in Roughing It (1872) that the lake was in a "lifeless, hideous desert ..." that was the "loneliest spot on earth ... little graced with the picturesque."
Naturalist John Muir explored the area in 1869. He described the "Mono Desert" as a "... country of wonderful contrasts. Hot deserts bounded by snow-laden mountains,—cinders and ashes scattered on glacier-polished pavements,—frost and fire working together in the making of beauty. In the lake are several volcanic islands, which show that the waters were once mingled with fire."  Muir described the Mono Craters as "... heaps of loose ashes that have never been blest by either rain or snow ..."In the spring of 1881 and the fall of 1882, geologist Israel Russell studied the area as a side-trip during his field research of Lake Lahontan, a now dry lake that covered much of nearby Nevada during the last glacial period. His Quaternary History of the Mono Valley (1889), which included a topographic survey by Willard D. Johnson, was the first thorough scientific description of Mono Lake and its volcanic features.
Russell named the Mono Craters and wrote: "The attention of every one who enters Mono Valley is at once attracted by the soft, pleasing colors of these craters as well as by the symmetry and beauty of their forms. They are exceptional features in the scenery of the region, and are rendered all the more striking by their proximity to the angular peaks and rugged outlines of the High Sierra.".

Answer: What is the name of the place that has two volcanic islands?


Question: Passage: Leonard Harrison State Park is a 585-acre (237 ha) Pennsylvania state park in Tioga County, Pennsylvania, in the United States. It is on the east rim of the Pine Creek Gorge, also known as the Grand Canyon of Pennsylvania, which is 800 feet (240 m) deep and nearly 4,000 feet (1,200 m) across here. It also serves as headquarters for the adjoining Colton Point State Park, its sister park on the west rim of the gorge. Leonard Harrison State Park is known for its views of the Pine Creek Gorge, and offers hiking, fishing and hunting, whitewater boating, and camping. The park is in Shippen and Delmar Townships, 10 miles (16 km) west of Wellsboro at the western terminus of Pennsylvania Route 660.
Pine Creek flows through the park and has carved the gorge through five major rock formations from the Devonian and Carboniferous periods. Native Americans once used the Pine Creek Path along the creek. The path was later used by lumbermen, and then became the course of a railroad from 1883 to 1988. Since 1996, the 63.4-mile (102.0 km) Pine Creek Rail Trail has followed the creek through the park. The Pine Creek Gorge was named a National Natural Landmark in 1968 and is also protected as a Pennsylvania State Natural Area and Important Bird Area, while Pine Creek is a Pennsylvania Scenic and Wild River. The gorge is home to many species of plants and animals, some of which have been reintroduced to the area.
Although the Pine Creek Gorge was clearcut in the 19th and early 20th centuries, it is now covered by second growth forest, thanks in part to the conservation efforts of the Civilian Conservation Corps (CCC) in the 1930s. The park is named for Leonard Harrison, a Wellsboro lumberman who cut the timber there, then established the park, which he donated to the state in 1922. The CCC improved the park and built many of its original facilities. Since a successful publicity campaign in 1936, the park has been a popular tourist destination and attracts hundreds of thousands of visitors each year. Leonard Harrison State Park was chosen by the Pennsylvania Department of Conservation and Natural Resources (DCNR) Bureau of Parks for its "25 Must-See Pennsylvania State Parks" list, which praised its "spectacular vistas and a fabulous view of Pine Creek Gorge, also known as Pennsylvania's Grand Canyon".

Answer: What is the name of the place whose sister park is on the west rim of the gorge?


Question: Passage: At the train station, Mr. Givney is doing some paper work when a rat pops out of a hole. After the rat eats his sock and belt, Mr. Givney pulls out a revolver and guns down the rodent. He then comes outside and orders Jerry to deal with the station's rat problem.
In no time Jerry comes up with using his saxophone. When Jerry plays on his instrument, the rats are mesmerized by the melody as they come out from various openings in the station. Jerry, while still playing, walks further from the station, and the rats follow him. Mr. Givney also comes along to see Jerry's handling.
Jerry lures the rats into a lake, hoping they would drown. Thinking the plan worked, Mr. Givney picks up Jerry like a beloved son, gives complimentary kisses, and carries him back to the station.
Back at the lake, a train stops to refill its boiler. The train engineer inserts a hose into the lake to take up water. It appears the rats are not completely drown as they pass through the hose.
Minutes later, the train arrives at the station. Jerry is excited, and Mr. Givney shows up. To their surprise, what comes out are the rats Jerry removed previously. Jerry and Mr. Givney then cling onto the edges of the door, and watch the rats run back into the openings inside.

Answer:
What passes through the hose when the train engineer inserts it into the lake?