| 摘要 |
A lid ( 2 ) for a container ( 67 ), the lid ( 2 ) comprising a first plastic layer ( 15 ) including a portion having at least one colored pigment and a second plastic layer ( 14 ) including at least one thermochromic substance capable of becoming translucent upon reaching a predetermined temperature in response to heat transfer from or to contents of the container so as to reveal the colored pigment of the first layer. Alternatively, there is described a lid comprising a layer with a portion ( 62,63 ) that becomes either observable or non-observable at the predetermined temperature.
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