Choose the right form. 1. There has been a snowstorm in the mountains. The roads couldn't/might not be
passable.
2. We should call Tim before going to his house; he couldn't/might not be there.
3. Unfortunately, James and Michelle have already made plans, so they couldn't/might
not come with us to the exhibition at the Museum of Contemporary Art.
4. Eve wants to go to the ballet, but she couldn't/might not be able to get time off that
evening
5. The video is gone. Doug must take/must not have taken/must have taken it.
6. Susan couldn't/might not hear the speaker because the crowd was cheering so
loudly.
7. Jerry couldn't/might not be angry at me. I've never done anything to upset him
​

im gonna take a guess and say gas vans and chambers

the purpose of the heading in the passage is to identify who is telling the story.

this excerpt is part of the book sugar changed the world (2010) written by marc aronson and marina budhos. as the book has been written by two people, the heading "marc" indicates that this specific excerpt is being narrated by aronson. in the fragment, marc describes his grandfather's story after hearing it from his cousin. however, there are other excerpts where budhos is the one that tells the story of her family.

aronson and budhos, who are husband and wife in real life, decided to write sugar changed the world when they found out how sugar, which had an important role in slavery and economy, changed their ancestors' lives.