A sentence is a （） concept, and the meaning of a sentence is often studied in isolation. ["pragmatic","grammatical","mental","conceptual"]
班训字数不能太多，一般在（）字左右。 ["3-6","4-8","4-12","8-12"]
超级市场
工业核仪表中常用的射线探测器有（）。 ["闪烁探测器","霍尔探测器","光电倍增管","电离室探测器"]
教育评价
怎样保证线带的准确运动，从而使输纸速度不受损失？
