Using the clinical trials dataset from the course web site, give XPath queries that return the data requested below:

EXAMPLE QUESTION:

All country elements residing anywhere in the document

EXAMPLE ANSWER:

//country

Q1. The second collaborating agency listed for each study

Q2. All enrollment nodes of type "Actual"

Q3. The nct_id of each study having a facility located in Toronto

Q4. For each study having at least one location in Canada, list all
    other countries involved in the study.

Q5. The condition of each study that discloses at least three
    arm_group elements

Q6. The nct_id and all city names of each study having an
    "Anticipated" enrollment of 250.

Q7. Output the nct_id, last_name of the overall_official, and first
    listed condition for each study with a location in Hershey,
    Pennsylvania, USA.

Q8. For each study location in Bangkok, give the nct_id of the study,
    the location's facility name, and last name(s) of any investigator
    or contact associated with that location.

Q9. For each study with at least one location in Germany, output the
    nct_id and -- for each German location in the study -- the
    location name, city, and investigator last_name associated with
    that location. Exclude studies spanning fewer than five locations
    and also exclude any study with a location in Austria.