You are given a paragraph, with numbered sentences, and a question. Write the numbers of the sentences needed to answer the given question. Separate multiple sentence numbers with a comma (", "). E.g. "1, 2" would be the correct response if Sent 1 and Sent 2 are needed to answer the given question (do not include sentences that contain no information that is necessary to answer the question). Sort the sentence numbers in an increasing order (i.e., '1, 2', instead of '2, 1'). Your answer should not contain anything than the sentence numbers separated by a comma (e.g. '1, 2, 3, 4'). The given question requires more than one sentence to answer. So, your answer must contain at least one comma (", ").

Example Input: Paragraph- Sent 1: The old vaulted church was stripped down: there was no cloth on the altar, just a DJ's toolkit and his beer.
Sent 2: Through the dark, I could see three bolts left in the wall from where they'd taken down the crucifix.
Sent 3: A confessional too beaten-up to have been sold was shaking in a way that suggested activity inside, and where the pews had been taken out, a couple hundred people were testifying to the DJ's moving sermon.
Sent 4: Rachel stepped forward into the crowd while I took a moment to drink in the ceiling's blue-lit, shadowed vault and the light-catching haze from who-knows-what rising between the DJ and the crowd.
Sent 5: There was a terrific echo, each beat reverberating inside of the next, and the old stained-glass windows rattled in their frames.
Sent 6: On the dance floor, people moved with their eyes closed and their hands in the air.
Sent 7: I danced with Rachel for a while, but then something by the bar seemed to be pulling her eyes.
Sent 8: She told me that she was heading for a drink and slipped out of the crowd.
Sent 9: When she hadn't come back halfway through the next song, I glanced over at the bar.
Sent 10: It was just a little set-up where someone had stacked a few crates and brought something alcoholic to share, mostly beer.
Sent 11: Rachel was standing with a plastic cup, looking like she was having a conversation, but I couldn't see anyone else there.
Sent 12: The next time the crowd split, I saw him.
Sent 13: He stood in front of a blue light, so I couldn't see him clearly, but what I saw was memorable.
Sent 14: He wore a jacket of what might have been blue velvet, and his hair gleamed black against his white skin.
Sent 15: The blue haze seemed to stop just shy of his pallor, setting off his striking face without illuminating its details, and his wrists flashed white in the darkness.
Sent 16: He didn't move, just stared and held his drink.
Sent 17: The next time I saw them, his mouth was moving.
Sent 18: She nodded and he took her arm.
Sent 19: I watched them through the crush of dancers as they squeezed along the wall, and the feeling came to me that something was very wrong.
Sent 20: Saturday morning, I woke up and saw that she still hadn't come home.
Question: What was left when the crucifix was taken down from the wall at the old vaulted church?.
Example Output: 1, 2.

Example Input: Paragraph- Sent 1: While glaciers erode the landscape, they also deposit materials.
Sent 2: Glaciers deposit their sediment when they melt.
Sent 3: They drop and leave behind whatever was once frozen in their ice.
Sent 4: Its usually a mixture of particles and rocks.
Sent 5: It can be of all sizes, called glacial till.
Sent 6: Water from the melting ice may form lakes or other water features.
Sent 7: Figure Moraine is sediment deposited by a glacier.
Sent 8: A ground moraine is a thick layer of sediments left behind by a retreating glacier.
Sent 9: An end moraine is a low ridge of sediments deposited at the end of the glacier.
Sent 10: It marks the greatest distance the glacier advanced.
Sent 11: A drumlin is a long, low hill of sediments deposited by a glacier.
Sent 12: Drumlins often occur in groups.
Sent 13: These groups are called drumlin fields.
Sent 14: The narrow end of each drumlin points in the direction of an advancing glacier.
Sent 15: An esker is a winding ridge of sand deposited by a stream of meltwater.
Sent 16: Such streams flow underneath a retreating glacier.
Sent 17: A kettle lake occurs where a chunk of ice melt as they are left behind as a glacier retreats.
Sent 18: When the huge chuck of ice melts it leaves a depression.
Question: What are the types of moraines?.
Example Output: 8, 9.

Example Input: Paragraph- Sent 1: In passing through these checkpoints, each of the hijackers would have been screened by a walk-through metal detector calibrated to detect items with at least the metal content of a .22-caliber handgun.
Sent 2: Anyone who might have set off that detector would have been screened with a hand wand-a procedure requiring the screener to identify the metal item or items that caused the alarm.
Sent 3: In addition, an X-ray machine would have screened the hijackers' carry-on belongings.
Sent 4: The screening was in place to identify and confiscate weapons and other items prohibited from being carried onto a commercial flight.
Sent 5: None of the checkpoint supervisors recalled the hijackers or reported anything suspicious regarding their screening.
Sent 6: While Atta had been selected by CAPPS in Portland, three members of his hijacking team-Suqami, Wail al Shehri, and Waleed al Shehri-were selected in Boston.
Sent 7: Their selection affected only the handling of their checked bags, not their screening at the checkpoint.
Sent 8: All five men cleared the checkpoint and made their way to the gate for American 11.
Sent 9: Atta, Omari, and Suqami took their seats in business class (seats 8D, 8G, and 10B, respectively).
Sent 10: The Shehri brothers had adjacent seats in row 2 (Wail in 2A, Waleed in 2B), in the firstclass cabin.
Sent 11: They boarded American 11 between 7:31 and 7:40.
Sent 12: The aircraft pushed back from the gate at 7:40.
Sent 13: Shehhi and his team, none of whom had been selected by CAPPS, boarded United 175 between 7:23 and 7:28 (Banihammad in 2A, Shehri in 2B, Shehhi in 6C, Hamza al Ghamdi in 9C, and Ahmed al Ghamdi in 9D).
Sent 14: Their aircraft pushed back from the gate just before 8:00.
Sent 15: Washington Dulles: American 77.
Sent 16: Hundreds of miles southwest of Boston, at Dulles International Airport in the Virginia suburbs of Washington, D.C., five more men were preparing to take their early morning flight.
Sent 17: At 7:15, a pair of them, Khalid al Mihdhar and Majed Moqed, checked in at the American Airlines ticket counter for Flight 77, bound for Los Angeles.
Sent 18: Within the next 20 minutes, they would be followed by Hani Hanjour and two brothers, Nawaf al Hazmi and Salem al Hazmi.
Question: What time did American 11 push back from the gate ?.
Example Output:
11, 12.