Does the sentence "Armed conflict broke out between John and Longchamp, and by October 1191 Longchamp was isolated in the Tower of London with John in control of the city of London, thanks to promises John had made to the citizens in return for recognition as Richard's heir presumptive." provide a valid answer to the question "When was Longchamp isolated in the Tower of London?"

A: yes

Does the sentence "The teacher-pupil ratio for primary schools in Tuvalu is around 1:18 for all schools with the exception of Nauti School, which has a teacher-student ratio of 1:27." provide a valid answer to the question "How long are females required to go to school?"

A: no

Does the sentence "Perhaps around 85 per cent of Old English words are no longer in use, but those that survived, to be sure, are basic elements of Modern English vocabulary." provide a valid answer to the question "About what percentage of Old English words are not present in Modern English?"

A: yes

Does the sentence "In the 18th century the differences among human groups became a focus of scientific investigation." provide a valid answer to the question "In what century did differences among human groups become a focus of science?"

A:
yes