In this task, we ask you to rewrite a sentence in simple English without changing its general meaning. Essentially, you want to make the sentence easier to read by using simpler words, utilizing more straightforward sentence structures, and omitting non-essential information etc.

[Q]: In marine sediments the biological production of methane , also termed methanogenesis , is generally confined to where sulfates are depleted , below the top layers .
[A]: In marine sediments methane is produced when sulfates are low .


[Q]: The iPhone 4S introduced a new automated voice control system called Siri , that allows the user to give the iPhone commands , which it can execute and respond to .
[A]: The iPhone 4S introduced a new automated voice control system called " Siri " .


[Q]: Throughout her reign , the Queen has made hundreds of state visits to other countries and tours of the Commonwealth ; she is the most widely travelled head of state .
[A]:
Since then , the Queen has made visits to most Commonwealth countries .