Final answer:
Tachycardia; Cardiogram; Gastroscopy
Step-by-step explanation:
A) Tachycardia is a medical term linking a word root (tachy-) with a suffix (-cardia).
B) Cardiogram is a medical term linking a combining form (cardio-) with a suffix (-gram).
C) Gastroscopy is a medical term linking a combining form (gastro-) with a word root (-scopy) and a suffix (-y).