Given a question and a context passage, generate the answer having the word or phrase from the context passage. Here, the answer should be a shortest continous span from the passage.

Example Input: Context: In the county, the population was spread out with 23.5% under the age of 18, 7.8% from 18 to 24, 28.5% from 25 to 44, 25.9% from 45 to 64, and 14.2% who were 65 years of age or older. The median age was 40 years. For every 100 females, there were 93.8 males. For every 100 females age 18 and over, there were 90.5 males. 
 Question: Which age group is smaller: 25 to 44 or 45 to 64?
Example Output: 45 to 64

Example Input: Context: In America, when the eighth graders leave the middle school, they are often worried about moving to the high school. It is a hard time for them, but it can be an exciting one as well. To make it easier, students need to get familiar with their school. Even though they've done this already in the middle school, it's still important to find where their classrooms are. Most schools take students to the high school for a visit at the end of their eighth grade year. And, most schools also have a freshman speech for parents and students before the first year begins. Sometimes the main office will give away a map of the school. This can help students and parents to find different places in the school. One way to know your high school more and make new friends is to join a club or play a sport. Schools often offer chances to join different clubs and sports. Fall activities begin in August before the first day of school. If you are not interested in sports, there are clubs for any interest, such as drama, dance, chess, photography, community service, etc. These clubs allow students from different grades. By joining an activity, students can find new friendships, not to mention improving their chances in future college applications . The school office will have a list of activities offered at the school and information on how to join them. What's more, to have a great start to a high school year, students can write down some of their worries, and ask for help from teachers and school workers. 
 Question: When do many schools take students to visit their new high school?
Example Output: at the end of their eighth grade year

Example Input: Context: Phthiriasis palpebrarum is an uncommon cause of blepharoconjunctivitis in which Pthirus pubis infest the eyelashes. We report a case of unilateral phthiriasis palpebrarum with crab louse. A 45-year-old man presented with conjunctival hyperaemia and moderate itching associated with irritation, and crusty excretions of the eyelashes in the left eye. Careful slit-lamp examination revealed many lice and nits in left eye and mild conjunctival hyperaemia. No abnormality was found in the right eye. On dermatologic examination, only one louse was found at the pubic area. The patient was treated effectively with petrolatum jelly (Vaseline) and 1% permethrin shampoo (Kwellada 1% shampoo). At the end of the first week no louse or nit was present on eyelashes and pubic area. 
 Question: What is the cause of Phthiriasis Palpebrarum?
Example Output:
pthirus pubis