Macroeconomics pls help

Which of these is a disadvantage of hydrogen fuel cells? a. engines that use hydrogen fuel are more efficient than gasoline-powered engines. b. the only emission produced by hydrogen fuel cells is water. c. hydrogen fuel is continually available and useful for heating. d. hydrogen fuel is often purified in a process that emits lots of greenhouse gases.

Does delivering the same message over and over again aid in persuasion? what is this technique and how does it work?

1. the or shop owner initiates the repair order. a. service manager b. foreman c. customer d. service consultant student a incorrect reference: section 5.1 2. the repair order is routed to the who computes the bill based on information supplied by the technician and shop policy. a. service manager b. foreman c. service consultant d. accountant student c incorrect reference: section 5.1 8. is used in windshield washer fluid to prevent freezing and dissolve bugs. a. propanol b. brake fluid c. alcohol-additive (methanol) d. ethylene glycol student a incorrect reference: section 5.3 9. all of these acts are performed when doing an oil and filter change except a. lifting the vehicle to your best working height. b. putting the drain pan under the oil-drain plug. c. using safety glasses with side shields. d. loosening the drain plug with a screwdriver. student c incorrect reference: section 5.2 10. coolant should be clear, not clouded from contamination, and should feel a. slippery. b. hot. c. cool. d. sticky. student c incorrect reference: section 5.3 11. the device in the above photo is used to check the coolant a. level. b. acid level. c. temperature. d. thickness. student c incorrect reference: section 5.3 14. some vehicles require the use of a to check the level of the fluid. a. scan tool b. micrometer c. feeler gauge d. manometer student d incorrect reference: section 5.3 17. the type of oil used in a vehicle is determined by the oem specifications and the oil which is listed in the owner’s manual, online service information, and on the oil fill cap. a. pressure b. viscosity c. density d. type student c incorrect reference: section 5.2 18. one of the first jobs a new technician does in the shop is a. tire service. b. transmission work. c. lubrication service. d. front-end work. student a incorrect reference: section 5.2 plzzz