Metric and English
no
The respiratory system and the nervous system are the two systems used when breathing hard
Two polymers , polythene and polyvinyl chloride are widely used in world.
The nervous and endocrine systems are the two systems responsible for controlling behavior.
The two most common systems of units are cgs and SI systems
The two most common systems for server operating are Windows and Mac OS X. These two systems for server operating are widely used and are the most well-know systems.
EDI is a standard used for all business documents, like Purchase Orders, Ship Notice, Ship Manifest, Invoices and Freight Bills. EDI standards are used by companies that wants to conform to standard way of transacting business documents. X12 and EDIFACT are two widely used EDI standards.
In the most widely used forms of arithmetic, two plus two is four, not one. However, in some forms of advanced mathematical systems, two plus two might end up being one, or even zero.
Firefox and Google Chrome but IE is also a widely used web browser.
no
The respiratory system and the nervous system are the two systems used when breathing hard
Msn and Yahoo
All your systems are used, otherwise you would not be living let alone running.
Two polymers , polythene and polyvinyl chloride are widely used in world.
Solar and Hydro electricity
"Momentarily" is widely used in speech to mean "in a minute or two,"
Found in your own question, the answer is "The" !