Matching Pairs Modal verbs in the pastOnline version Connect these two columns and construct sentences in the passive voice using should and shouldn't to comment on historical mistakes made by mankind. by Segni 1 Slavery 2 The cause of the Mary Celeste's mysterious desertion 3 The Pyramids of Giza 4 The identity of Jack the Ripper 5 The Berlin Wall 6 Apartheid 7 The atomic bombs 8 should not have been practiced in South Africa should not have been constructed during the Cold War could have been a giant squid. might never have been discovered should not have been dropped on Hiroshima and Nagasaki might have been built by aliens The disappearance of Amelia Earhart may have been caused by engine failure. should not have been allowed to exist in the United States