Try to find it here - bit(dot)ly/32TPpvU
I would say A. tunneling into the sides since gerunds contains ing's and it acts as a noun.
I hope this helps!
Here are about 20 options for a career choice, but I think there are more than just these. Hope this helps!
Probation Officer
Forensic Science Technician
Police Officer
Correctional Officer
Private Detective
Fish and Game Warden
Security Guard
State Trooper
Crime Scene Investigator
Computer Forensics Investigator
FBI Agent
Fraud Investigator
CIA Agent
US Postal Inspector
Immigration and Customs Enforcement Agent
Blood Spatter Analyst
Homicide Detective
DEA Agent
Secret Service Agent
US Marshal
"Using an illustration, my science teacher explained how the weather cycle works. "
is correct.
