1. Using one type of line make composition pithy and style less.

2. Composition with different lines is more vivid and enriched than one type of line.

3. Lines with different weight can show the movement of line and make the whole composition more various.

4. Line velocity could be changed by the change of width and angle.

5. Continuous line is smooth and can show real staffs while discontinuous line can express some visionary objectives and make audience imagine.

6. It shows unlimited space to audience and makes audience imagine.

7. An areal that several lines link could move our eyes around the composition.

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