"笔管"是个多义词，它可以指笔管（布依族乐器）,笔管（汉语词汇）。
向中国市场出口加州笔管鱼及带鱼。
而且你若没把笔管握成九十度垂直，就完全写不出来。
And if you didn't hold the pen exactly 3 vertical, it wouldn't write at all.
笔盖，笔管，笔管后盖，可以用来确认尺寸（小部分还会要修正）。
We can use them to check and confirm the final dimensions. Of course some modifications are still needed.
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