46. A. In spite => Despite
47. A. Despite of => Despite
48. C. less => spend
49. A. didn't => Because
50. B. had g went
51. B. because of => because
52. D. meaningful movie => see a meaningful movie
Corrected sentences:
46. Despite her severe pain, she tried to walk to the auditorium to attend the lecture.
47. Despite growing industrial activity, the majority of the American people continued to make their living from farming until the beginning of the 20th century.
48. Because of the invention of machines such as vacuum cleaners and washing machines, women spend less time doing the housework.
49. John didn't go to work because he was seriously ill.
50. Last night, I went to bed after I had finished my homework.
51. Peter succeeded in his exam because he worked hard and methodically.
52. They are going to the cinema this weekend so that they can see a meaningful movie.