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".

Ex Input:
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

Ex Output:
Yes

Ex Input:
After the disruption of the plot in Amman, it had not escaped notice in Washington that Hijazi had lived in California and driven a cab in Boston and that Deek was a naturalized U.S. citizen who, as Berger reminded President Clinton, had been in touch with extremists in the United States as well as abroad. Before Ressam's arrest, Berger saw no need to raise a public alarm at home- although the FBI put all field offices on alert. Now, following Ressam's arrest, the FBI asked for an unprecedented number of special wiretaps. Both Berger andTenet told us that their impression was that more Foreign Intelligence Surveillance Act (FISA) wiretap requests were processed during the millennium alert than ever before. The next day, writing about Ressam's arrest and links to a cell in Montreal, Berger informed the President that the FBI would advise police in the United States to step up activities but would still try to avoid undue public alarm by stressing that the government had no specific information about planned attacks. At a December 22 meeting of the Small Group of principals, FBI Director Louis Freeh briefed officials from the NSC staff, CIA, and Justice on wiretaps and investigations inside the United States, including a Brooklyn entity tied to the Ressam arrest, a seemingly unreliable foreign report of possible attacks on seven U.S. cities, two Algerians detained on the Canadian border, and searches in Montreal related to a jihadist cell. The Justice Department released a statement on the alert the same day. Clarke's staff warned, "Foreign terrorist sleeper cells are present in the US and attacks in the US are likely." Clarke asked Berger to try to make sure that the domestic agencies remained alert." Is there a threat to civilian aircraft?"he wrote. Clarke also asked the principals in late December to discuss a foreign security service report about a Bin Laden plan to put bombs on transatlantic flights. The CSG met daily. Berger said that the principals met constantly. Later, when asked what made her decide to ask Ressam to step out of his vehicle, Diana Dean, a Customs inspector who referred Ressam to secondary inspection, testified that it was her "training and experience." It appears that the heightened sense of alert at the national level played no role in Ressam's detention. There was a mounting sense of public alarm. The earlier Jordanian arrests had been covered in the press, and Ressam's arrest was featured on network evening news broadcasts throughout the Christmas season. The FBI was more communicative during the millennium crisis than it had ever been. <sep>On what date did the warning "Foreign terrorist sleeper cells are present in the US and attacks in the US are likely." take place?<sep>Christmas day

Ex Output:
No

Ex Input:
Callimaco is taken by the beauty of Lucrezia , but she is the loyal wife of Nicia , a rich and foolish lawyer . Callimaco hires the service of a shady ' fixer ' named Ligurio to aid in his quest to sleep with her . Lgurio informs Callimaco that Nicia and Lucrezia are anxious to have a child . With the fixer's help , . Callimaco masquerades as a doctor and convinces Nicia that the best way for Lucrezia to conceive a child is by her taking a potion made from the Mandrake Root . He lies and warns Nicia that the first man to sleep with Lucrezia after she has taken the potion will die within eight days . Together they devise a plan to kidnap a stranger to sleep with Lucrezia and draw out the poison . Callimaco then disguises himself and arranges to be the one who is kidnapped . Lucrezia is an honorable woman and does not at first agree to meet with the stranger . Nicia gets both Lucrezia's mother , a woman of ill repute , and her confessor Brother Timoteo , a priest of low morals , to aid in convincing Lucrezia of the necessity of the plan . After finally sleeping with Lucrezia , Callimaco confesses everything . Lucrezia gives thought to the duplicity of her husband , her mother , and her confessor , and decides that she now wants Callimaco as a lover forever . Callimaco gets what he had desired and everyone else continues to believe that each had outwitted the others . <sep>Who finally slept with Lucrezia?<sep>The fixer

Ex Output:
No