Which biome's yearly rainfall mainly evaporates?

Two technicians are discussing a resistance measurement between the can-h and can-l wires. technician a says this measurement should be done with the ignition switch in the "run" position. technician b states that a measurement of 0 ohms indicates an open in the network. which technician is correct?

Because light travels in a straight line and casts a shadow, isaac newton hypothesized that light is

Convection currents are caused by differences in what two things?