English Skills 10th Edition by John Langan, Zoe Albright

Exercise 17

Locate the split in each of the following run-ons. Each is a fused sentence -that is, each consists of two sentences that are fused, or joined together, with no punctuation between them. Reading each fused sentence aloud will help you "hear" where a major break or split in the thought occurs. At such a point, your voice will probably drop and pause.
Correct the run-on by putting a period at the end of the first thought and a capital letter at the start of the next thought.
EXAMPLE
Martha Grencher shuffled around the apartment in her slippers. Her husband couldn't stand their slapping sound on the floor.
Last week a student brought a gun to school the principal has now decided to install metal detectors at the school's entrance.