It was scary when there was a lockout at school
My towing company provides lockout service.
Lockout Detroit
The subject of the sentence typically contains a noun.
Lockout New Braunfels
Lockout was released on 04/13/2012.
The Production Budget for Lockout was $20,000,000.
A mathematical sentence that contains an equals sign would be called an equation.
This sentence contains the word fortifying.
A Lockout.
If you mean what sentence in the paragraph contains the main idea then it would be the topic sentence and the rephrased version of the conclusion.
lockout
The compound sentence "I went to the store, and then I visited my friend" contains correct punctuation.