ambient
(1)围周的，环境的
(2)大气的
(3)背景的

• proportional scale
• proportioner
• proportion facotr
• propulsion
• prostate gland
• prostatic lumen
• protactinium
• protanope
• protanopia
• protectant
• protecting cover
• protecting glass
• protecting screen
• protection
• protective agent
• protective coating
• protective glass
• protective glass plate
• protective goggles
• protective head-cover
• protective inorganic coating
• protective layer
• protective metal shell
• protective paint
• protective shield