fine-tooth comb
/ˈfaɪntuːθ/(亦作fine-toothed comb)
noun
1- a comb with narrow teeth that are close together细齿梳; 篦子。
1.1
- in sing. used with reference to a very thorough search or analysis of something仔细搜查（或检查、分析）：
you should check the small print with a fine-tooth comb.
你应当仔细审查用小号字体印刷的附属细则。参见TOOTHCOMB.