The security guard stood outside the gates.
There is a security near the house.
Security as airports is intense. People lock their doors for security reasons.
John had to call security to watch over his home.
A security guard is posted at the gate of the mental hospital.
The complex sentence is "After you install the security software, your computer will run smoothly." This sentence contains an independent clause ("your computer will run smoothly") and a dependent clause ("After you install the security software"), which makes it complex. The other sentence about the technician is a compound sentence, and the last sentence is incomplete.
He has job security because he's been here so long. She need to find security in her next relationship.
yes you would capatalize Social Security in a sentence.
She was granted admittance to the security room.
The state of the Department's security was truly deplorable.
A linguist could breach their security.
Security made us egress the building
The embassy's security system is doubly redundant.