In this task, you will be presented with a context passage, a question about that paragraph, and a possible answer to that question. The task is to check the validity of the answer. Answer with "Yes" or "No".

Q: Fossils can be used to match up rock layers. As organisms change over time, they look different. Older fossils will look different than younger fossils. Some organisms only survived for a short time before going extinct. Knowing what organisms looked like at certain times also helps date rock layers. Some fossils are better than others for this use. The fossils that are very distinct at certain times of Earths history are called index fossils. Index fossils are commonly used to match rock layers. You can see how this works in Figure 2.30. If two rock layers have the same index fossils, then they're probably about the same age. <sep>What kind of fossils are used to date rock layers?<sep>Index fossils

A: Yes
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Q: Alien Planet starts out with an interstellar spacecraft named Von Braun , leaving Earth's orbit . Traveling at 20 % the speed of light , it reaches Darwin IV in 42 years . Upon reaching orbit , it deploys the Darwin Reconnaissance Orbiter , Which looks for potential landing sites for the probes . The first probe , Balboa , explodes along with its lifting body transport during entry , because one of its wings failed to unfold . Two backup probes , Leonardo da Vinci and Isaac Newton , successfully land on the planet , and learn much about its bizarre indigenous lifeforms , including an apparently sapient species . The robotic probes sent out to research on Darwin IV are called Horus Probes . Each Horus probe consists of an { { convert } } long inflatable , hydrogen-filled balloon , Which is covered with solar receptors , a computer ' brain ' , a ' head ' covered with sensors , and several smaller robots that can be sent to places too dangerous for the probes themselves . The probes have a limited degree of artificial intelligence , very similar to the ' processing power ' of a 4-year-old . All the real thinking is done by a supercomputer in the orbiting Von Braun . The probes are programmed with different personalities ; Ike is more cautious , while Leo is the risk-taker . The two probes are also equipped with a holographic message that will be projected to any sentient life found on Darwin . After the two probes inflate their gas-bags , they encounter a voracious Arrowtongue and watch it pursue a Gyrosprinter . <sep>What are the different types of probes on the Von Braun?<sep>Horus Probes

A: Yes
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Q: Tim had always a red bike. His birthday party was coming up and he hoped that his parents would finally get him the bike. When his friends came over for the party, Tim was very worried that he wouldn't get the bike. He looked at all the presents and none of them seemed big enough to have a bike in them. Tim was sad. When it was time to open the presents he opened them one at a time. The first present was not a bike. The second present was not a bike. The third present was the biggest one. Tim knew if the bike was going to be in any of the presents it was going to be in this box. Tim opened it and there was no bike inside. Just as Tim tried not to look too upset, his Dad brought in the biggest present of them all. His Dad had been hiding the present all along. Tim opened it and his new bike was inside the box. Tim put the bike together with his Dad's help. <sep>How many presents did Tim open before opening his bike?<sep>3

A:
Yes
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