... Many people _ of malaria, smallpox before the process of vaccination was invented in the 19 th century a have died b had died c would die d were dying 41 Our government _ a system of private ... Tuberculosis _ an infectious disease a was b has been 37 Pasteur _ in the 19 th century a was living b lived 38 Since 19 80, scientists the world over _ a lot of things to fight against AIDS ... visit 49. _ to rain before you woke up this morning? a Did it begin b Has it begun c Had it begun d Would it begin 50 My daughter saw an elephant this morning but she _ one before a had never seen...