calibration

"My friend told me there was something in the box, but I didn't know what it was yet. "

"The science teacher conducted an experiment to demonstrate how plants grow in different types of soil. "

"The school is located five miles of the town center. "

"The teacher ensured her students that the test would cover only the topics they studied in class. "

"accurate knowledge"

"I saved money for a new car."

"The scientist is calibrating the lab equipment to ensure accurate measurements. "

"It looks weaker and weaker, the more I think about it."

"My science teacher took the class to the lab to perform experiments. "

"The camping equipment was essential for a successful weekend trip. "

"the result of a course of action;  the result of a mathematical operation"

"an act of goodwill"