Does the plan work?
Brad was a student in my after-school tutoring session. He was working ___LESS___ than diligently.
“Brad,” I said, “I talked to your mom, and she wants you to stay for the full hour, so you may as well get something done.” “She wants you to keep me every day for an hour?” he complained. “She wants you to learn it’s ___EASIER___ to work during regular class hours than to give up after-school time.” Brad seemed to agree.
“So,” I continued, “why not get your work done now so you can bring your marks up and get your mom off your back?” “No!” he replied in horror. “If I ___GET___ good marks now, she’ll think this plan is working, and she’ll keep me in here until June!”
Why a zigzag?
Have you ever noticed that when we climb hills we create zigzags? We don’t go straight ahead but go in zigzags. It can mean walking 20 times as far, and still a zigzag is ___FASTER___ than the shortest distance between two points.
Researchers developed a mathematical model ___SHOWING___ that a zigzag provides the most efficient way for humans to go up or down steep slopes. They explain that zig-zagging ___REQUIRES___ less effort.
Do you know Russian rivers? Do you know what the ___LONGEST___ river in Russia is? It is the Volga River. This river is a great source of hydroelectric power. The water from the river ___IS_USED___ for irrigation. Canals link the Volga River to the Baltic and White Seas. The Volga ___FREEZES___ for most of its length for three months each year.