1.are bevs or hydrogen fuel cell vehicles a more promising transportation technology for the future?
2.should car companies be required to produce electric cars?

According to social exchange theory, altruistic behaviors benefit the individual who performs them. t/f

If the wheels lock when braking suddenly the vehicle: a: loses traction b: lose steering wheel ability c: gain speed slightly d: gain steering ability

Light from a sodium lamp passes through a diffraction grating that has 1000 slits per millimeter. the interference pattern is viewed on a screen 1.000 m behind the grating. the first (m = 1) two bright yellow fringes that are visible are 0.7288 m and 0.7300 m from the central maximum. what are the wavelengths of these two fringes?