2. XPath

a)      //continent
        //continent/name/text()
	/mondial/continent/name/text()

b)      //country[border/@country='D']/name/text()

c)      //country[count(ethnicgroups)>10]/name/text()

d)      //island[located/@country='GB']/name/text()


3. XQuery

a)

for $c in doc("mondial.xml")//country
order by number($c/@area) descending
return $c/name/text()


b)

<countries>
{
   for $c in doc("mondial.xml")//country
   return <country>{$c/name/text()}</country>
}
</countries>

c) self-join

for $c1 in doc("mondial.xml")//country
for $c2 in doc("mondial.xml")//country
where $c1/@car_code=$c2/border/@country
return <neighbor> {$c1/name/text()} - {$c2/name/text() } </neighbor>

-> without duplicates

for $c1 in doc("mondial.xml")//country
for $c2 in doc("mondial.xml")//country
where $c1/@car_code=$c2/border/@country
      and $c1/name < $c2/name
return <neighbor> {$c1/name/text()} - {$c2/name/text() } </neighbor>

d) join of 2 documents

for $c in doc('mondial.xml')//country
for $s in doc('hamlet.xml')//*
where contains($s/text(),$c/name/text())
return <occ>
<c>{$c/name/text()}</c>
{$s}
</occ>