......)

2.①

Polka's activities (2)

The elegance of waltz

3. Sentence ① in the text belongs to (hypothetical) question; (2) This sentence belongs to (inverse) question. No one dares to take it lightly. It just depends on heredity. Birds have wisdom and instinct.

4. The author writes about bird watching, including interesting scenes such as (feeding), (breeding birds) and (migrating), briefly describing (having children, nesting, avoiding enemies, clearing up after the rain), expressing oneself (loving birds) and enlightening people (living in harmony like birds).

5. Read the third paragraph with emotion and answer the questions.

The first floor (the first sentence): Birds have harmony.

The second floor (from spring to summer): During the breeding period, birds are busy building nests and brooding. They don't bother each other.

The third layer (thus reaching the grassland in winter): Birds have different foraging skills.

The fourth floor (the last sentence): True harmony is to get what you want, and not to want anything.

Harmony is mentioned at the beginning and end of this passage; What the author wants to explain is: now people are destroying the harmony of nature, so we should protect nature;

The enlightenment to mankind is that people should first understand harmony, live in peace with animals and live together in this world.