What does a vertical line to the left of multiple staves indicate to a musician?

Axel is thinking abou replacing the word astounded. which word would best to make the tone of the sentence more negative? a) surprised b) shocked c) astonished d) amazed

This is just a little thing i just did for fun! hope you enjoy! a: ~what would you first grand if your house was onfire? b: ~what do you first notice on a person? c: ~ what are some challenges you think the next generation will face? d: ~what is the most embarrassing moment in life? e: ~what is your favorite artists? //music//f: ~what are some bad habits you can't stop doing? , but you know you need to stop on them.i really hope you had fun doing this, or not doesn't matter, but if you want more from me contact me! bye now//i can't wait to see some results//ㅋㅋㅋㅋㅋ나를 따라라! ^^(i'm going to put this under arts, even though it's not, so yeah)

Need some ! asap i need to figure out 3 major changes in bridges over time and why these changes to adapt to both improvements in technology and changing social links would also alot.