hi, i'm having trouble with some of an assignment. I have been required to design a xml schema for the following problem:

A travel company wants you to design a new XML language using an XML
Schema as the definition. They have the following requirements: The XML
documents are about vacations and should contain customer details and resort
details. Customers have customer numbers as well as names and addresses.
They also have a number in party (adults and children).
Resorts have addresses, descriptions and facilities. Whilst the addresses and
descriptions are mandatory, it is recognised that not all resorts will have the
same facilities.
Facilities in typical resorts include: beach (inc. distance from resort), golf (total
number of holes: 18, 36, etc), swimming pool(s), gymnasium, crèche.

So far this is what I have come up with:

<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified">
<xs:element name="vacations">
<xs:complexType>
<xs:sequence>
<xs:element name="customer_details">
<xs:complexType>
<xs:sequence>
<xs:element name="customer_number" type="xs:integer"/>
<xs:element name="customer_name" type="xs:string"/>
<xs:element name="customer_address" type="xs:string"/>
<xs:element name="number_in_party">
<xs:complexType>
<xs:sequence>
<xs:element name="adults" type="xs:integer"/>
<xs:element name="children" type="xs:integer"/>
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:sequence>
</xs:complexType>
</xs:element>
<xs:element name="resort_details">
<xs:complexType>
<xs:sequence>
<xs:element name="addresses" type="xs:string"/>
<xs:element name="descriptions" type="xs:string"/>
<xs:element name="facilities">
<xs:complexType>
<xs:sequence>
<xs:element name="beach" type="xs:string"/>
<xs:element name="golf" type="xs:string"/>
<xs:element name="swimming_pool" type="xs:string"/>
<xs:element name="gymnasium" type="xs:string"/>
<xs:element name="creche" type="xs:string"/>
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:sequence>
</xs:complexType>
</xs:element>
</xs:schema>

I'm abit confused on the part where it say not all resorts will have the same facilities and think i am required to show this in my scheme? how do i go about doing that?