zhè / kuài / hēi / bǎn / kāi / yǐ / jīng / yòng / jiù / le / cā / qǐ / lái / bù / tài / gān / jìng

这块黑板揩已经用旧了，擦起来不太干净。

This blackboard eraser is worn out, so it does not clean very well.