2. Features: Use parallelism rhetoric.

Expression effect: majestic and powerful, with strong appeal and appeal. (That's right)

"This dream" means that blacks can have the same freedom and equal rights as whites. The "American Dream" refers to a common slogan, that is, the ideal of building democracy, equality and freedom in the country advocated by the United States. (That's right)

4. "Harsh quarrel" refers to the congressional discussion on whether to give black people political rights and how much rights to eliminate racial discrimination. "Beautiful Symphony" refers to equality and freedom for all. (That's right)