user: Please give me a summary of the current rule set for roller derby.

assistant: <think>
Roller derby is played in two periods of 30 minutes.: 4  Two teams of up to 15 players each field up to five members for episodes called "jams". Jams last two minutes unless called off prematurely.: 5  Each team designates a scoring player (the "jammer"); the other four members are "blockers". One blocker can be designated as a "pivot"—a blocker who is allowed to become a jammer in the course of play.: 7  The next jam may involve different players of the 15 roster players, and different selections for jammer and pivot.: 7 

During each jam, players skate counterclockwise on a circuit track. Points are scored only by a team's jammer. After breaking through the pack and skating one lap to begin another "trip" through the pack, the jammer scores one point for passing any opposing blocker.: 33 [note 1] The rules describe an "earned" pass; notably, the jammer must be in-bounds and upright. The jammer's first earned pass scores a point for passing that blocker and a point for each opponent blocker not on the track (for instance, serving a penalty, or when the opposition did not field five players for the jam). If the jammer passes the entire pack, it is a four-point scoring trip, commonly called a "grand slam".[note 1]

Each team's blockers use body contact, changing positions, and other tactics to help their jammer score while hindering the opposing team's jammer.</think>
A roller derby bout consists of two 30 minute halves.
Players will be on the track for a series of two minute intervals.Each team will have 5 players on the track at one time. 
Four players from each are designated blockers, and will play both offense and defense at the same time.
Each team will field one jammer who is the main point scoring skater.
Jammers earn points for passing blockers from the opposing team.

user: Extract the list of science fiction awards from the paragraph below in the form of bulleted list, each item should include award name and whom is it presented by.

assistant: <think>
Among the most respected and well-known awards for science fiction are the Hugo Award for literature, presented by the World Science Fiction Society at Worldcon, and voted on by fans; the Nebula Award for literature, presented by the Science Fiction and Fantasy Writers of America, and voted on by the community of authors; the John W. Campbell Memorial Award for Best Science Fiction Novel, presented by a jury of writers; and the Theodore Sturgeon Memorial Award for short fiction, presented by a jury. One notable award for science fiction films and TV programs is the Saturn Award, which is presented annually by The Academy of Science Fiction, Fantasy, and Horror Films.</think>
- Hugo Award for literature, presented by the World Science Fiction Society.
- Nebula Award for literature, presented by the Science Fiction and Fantasy Writers of America.
- John W. Campbell Memorial Award for Best Science Fiction Novel, presented by a jury of writers.
- Theodore Sturgeon Memorial Award for short fiction, presented by a jury.
- Saturn Award, presented by by The Academy of Science Fiction, Fantasy, and Horror Films.

user: Identify which instrument is string or percussion: Rock gong, Yazheng

assistant: Yazheng is string, Rock gong is percussion.