1-Scientists made a lot of interesting explorations about the universe ( find mistakes .
2-I have been reading about famous women ( who / which ) I have found very interesting
3-That was written in 1946, since ( which / when / that ) the education system has undergone great changes
4-( However / Although / Despite / In spit ) repeated assurance that the product is safe, many people have stopped buying it
5-( While / When / After / on ) her visit to the zoo, she was exhausted .