How do you talk to people on here? I im trying to talk with my friend, so I click his profile, press messages, and it says this, can someone help?? 15 points

Technician a says that if a valve is open when a piston rises to the very top of a cylinder, the piston may actually strike the valve head and cause serious engine damage. technician b says if the camshaft is located in the engine block, then the engine is called an overhead valve engine, ohv engine, or an in-block camshaft. who is right? a. b only b. both a and b c. a only d. neither a nor b

Which action is good business etiquette? a. switching your cell phone off before you enter a meeting b. keeping your cell phone on low volume before you enter a meeting c. setting a pleasant ring tone on your cell phone before you enter a meeting d. setting a standard ringtone on your cell phone before you enter a meeting

The north and south regions had very diferent economies in the 1800s.