[Question]
select input elements with the readonly attribute specified

[Answer]
input:read-only

[Question]
select all <div> elements and all <p> elements

[Answer]
div, p

[Question]
select all elements with class_name_a and class_name_b within it's class name

[Answer]
.class_name_a.class_name_b

[Question]
select all <p> elements that are the second child of it's parent

[Answer]
p:nth-child(2)

[Question]
select all elements with attribute attribute_name starting with attribute_value

[Answer]
[attribute_name^='attribute_value']

[Question]
select all elements with attribute attribute_name containing attribute_value as a sub string

[Answer]
[attribute_name*='attribute_value']

[Question]
select all elements with attribute attribute_name containing attribute_value as a whole word

[Answer]
[attribute_name~='attribute_value']

[Question]
select all <p> elements inside <div> elements

[Answer]
div p

[Question]
select the document's root element

[Answer]
:root

