How many compression rings in marine engines normally have?

Can someone help me with this subject? "Know your car"?

• True or False questions 1. You will need a manufacturer's service manual to perform most basic under-the-hood maintenance on your car. 2. During the four stroke cycle of an individual piston, the crankshaft completes two revolutions, and the camshaft completes one revolution. 3. Late model cars with high performance engines often have two intake and two exhaust valves per cylinder. 4. When rings and cylinders in a car engine wear out, compression pressure is reduced, and a thick black smoke is produced. 5. When compression is being lost mainly through the valves then a complete engine overhaul may not be necessary.

• Answer:

  They're all true except possibly the first. I know that I can get under the hood of any car, without a manual, and do basic maintenance. It's all the same because it's... basic. You sure that one isn't a trick question?