The type of two-stroke engine that uses a spinning plate with a hole in it to control the flow of fuel to the cylinder is called a a. plate-port engine. b. rotary-valve engine. c. reed-valve engine. d. piston-port engine.

30 points - when can a theory be modified if a new type of technology allows for new observations that raise new questions? a. immediately, while the questions about the theory are being asked b. after new hypotheses related to the theory are tested in experiments c. only after the new observations disprove all parts of the theory d. while scientists begin to think about how the theory could improve

How to tell if a molecule is polar or nonpolar with electronegativity

Complete the sentence to describe the law of conservation of energy. the law of conservation of energy states that energy cannot be created