The two types of bright nebulae are emission nebulae and _______________ nebulae.
a. photonic
b. absorption
c. refraction
d. reflection
Question 2
A 10- resistor and a 20- resistor are connected in parallel, and this combination is connected in series to a 30- resistor. If the arrangement is hooked to a 12-V battery, how much current flows in the circuit?