Conditional MySQL select AND OR in PHP

Hello,

I would like to select rows from my mysql database that match:

ConditionA1 AND ConditionA2
OR
ConditionB1 AND ConditionB2
OR
ConditionC1 AND ConditionC2
etc.

I know I have to use:
mysql_query(“SELECT * FROM tbl WHERE ConditionA1 = ‘$vrbl’ AND ConditionA2 = ‘$vrbl’…..

But I am a not sure how to add the OR bit for the second two conditions..

Thank you for your help ?

Also in #PHP _↴