Complete the sentences with the Present or Past Passive form of the verbs in brackets.

a) Chaos ............................................................ (cause) by a hurricane and heavy floods.
b) In 1957, the lives of many people ............................................................ (affect) by a train disaster.
c) The country ............................................................ (hit) by a major earthquake in 1997.
d) Every year, the greatest amount of energy ............................................................ (use) by the chemical industry.
e) Now, millions of products ............................................................ (sell) online.
f) Sustainable energy sources ............................................................ (need) for a cleaner environment.