a) Like chargs attract; unlike charges repel.
b) When polythene is rubbed with wool, positive charges move from the polythene to the wool.
c) Metal water pipes in the home can be used as an electrical earth.
d) The tip of a lightning conductor should have a sharp point.
e) It could be dangerous to fly a kite during thundery weather.
f) Blobs of solder on electrical equipment should be rounded rather than pointed.
g) A conductor allows protons to move through it easily.
更新1:
for c to f can you give a reason for them