Dont judge me friends

Ben is interested in using a source that provides original research, current and developing trends and experts within specific fields. which source should he use?

Iknow this isn't a question, but is there someway to ask a question under public safety or is there no category for it? i don't know if i'm overlooking it or not.

Certain gases in air are important natural resources that are used in welding. two of these gases are a. oxygen and argon b. hydrogen and fluorine c. chlorine and sulfur dioxide d. nitrogen and carbon dioxide