The plant detects the substance and activates an internal signal that causes it to lose its green colour, turning its leaves white.

当植物监测到那些有害物品时就会激发内信号，使叶子从绿色变成白色。

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Yellow is a traditional tie colour in countries, including England, which can signal assuredness, along with radiance and vitality, he said.

他说，在很多国家，包括在英国，黄色是传统的领带色。它给人一种自信、活力的跃动感。

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The principle and method for calibrating the frequency by means of colour subcarrier signal of broadcast TV are introduced in detail, and the corresponding measurement accuracy is given in this paper.

本文较详细介绍利用广播电视彩色付载频信号进行校频的原理和方法，并给出相应的测量精度。

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The role of the magno cells is to signal contrasts in brightness, while the parvo cells react to both brightness and colour.

ECONOMIST: The biology of art

Forte features a colour OLED (Organic LED) display to indicate input and output signal levels, mic preamp gain and other useful information, with stylish motion graphics giving you detailed visual information.

ENGADGET: Focusrite launches Forte, 24-bit / 192kHz portable audio interface (video)