发痛物质,引起疼痛的物质,致痛物质的英文

pain producing substance

• 发:    hair
• 物质:    matter; substance; ...
• 引起:    give rise to; lead ...
• 疼痛:    pain; ache; sorene ...
• 的:    4次方是 The fourth po ...
• 致:    deliver; send; ext ...