2. metaphor, parallelism. Lack of lines: abstract and unpredictable. No solution: no reason or answer is needed. Cuddle: "Missing line" and "No solution" are used to describe "wall chart" and "algebra" and express the center "lack", so we should analyze it in connection with the characteristics of "lack". ?
3. The anxiety of "missing" is vividly illustrated by metaphor.
4. The first two sentences: have a sense of time and space (or: a long time, a long distance); The last two sentences: I have a thousand words in my heart that I want to say, but it is difficult to express.
Example: (What is missing is) a thin piece of writing paper (What is missing is) a green olive (the answer is not unique).