Solar energy is ­______ and inexhaustible? Solar power does not cause ______

NB 1. Solar energy is ­______ and inexhaustible.
NB 2. Solar power does not cause ______.
TH 3. In remote areas ………………. can be created from solar energy.
VD 4. It is inconvenient for people to use ……...at nights or on cloudy days.