15. 下列何者通常以雙過濾器設計？ (A) 粗過濾器 (B) 細過濾器 (C) 精細過濾器 (D) 空氣過濾器

6. Which is not one of instructions for safety precautions described in the working manual？ (A) Precautions for handling the low temperature or low pressure spot. (B) Installing fire extinguisher and first aid kit. (C) Be cautions with the asbestos dust. (D) Precautions for handling the high temperature or high pressure spot.