They believe in devils and demons and thought witches gained power from the devil
The answer is:
A diagram with each part of the bicycle labeled.
Due to the fact that the text deals with a technical procedure such as changing the chain of a bicycle, the writer should reinforce the information including a graphical representation of the different bicycle parts. As a consequence, readers would be provided with a pictorial aid to understand the text better.
To look at someone with pleasure
The correct answer is that - science progressed rapidly during this time.
Victorian era was a time of progress in scientific terms - many discoveries of the time affected the lives of Victorians in a positive way that helped them living their lives immensely. This was the time when the sewing machine was invented, when Charles Darwin wrote his "The Origin of Species," when Louis Pasteur worked on vaccines and studied pasteurization, etc.