| Reasons | F1 | F2 | F3 | F4 | F5 | M1 | M2 | M3 | M4 | M5 |
| 1) Low understanding abilities | l | l | l | l | l | l | l | l |
| l |
| 2) Poor observation and attention | l | l | l | l | l | l | l |
| l | l |
| 3) Low ability to accept new things |
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| l |
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| l |
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| 4) Visual impairment |
| l | l |
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| 5) Poor memory | l |
| l |
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| l |
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