Alternative possibilities are that they use signals from ocean currents, water temperature or smell.

另外，他们可能利用洋流信号，水温或气味。

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The results indicated that root-divided alternative irrigation could increase root activities, photosynthesis rate and water use efficiency of tobacco leaf, but decrease transpiration rate;

结果表明，分根交替灌溉可增强烟株的根系活力，保持较高的光合速率，降低蒸腾速率，提高叶片瞬时水分利用效率；

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Use alcohol-based hand sanitizers as an alternative to hand washing when soap and water aren't available.

CNN: Sore throat