生物學家發現了世界上最小的潛水哺乳動物 —— 水鼩的基因秘密。

Water shrews are diminutive, long-snouted mammals. They weigh less than one AA battery, and lose heat quickly, and burn energy constantly in tiny active muscles.

水鼩是一種體型纖小、長吻的哺乳動物。這類動物的體重還不足一節 AA（5號）電池，它們體內的熱量會迅速流失，微小的活動肌肉中不斷燃燒著能量。

But the ability to feed on all the insect larvae that live on the beds of rivers and streams has driven them to forage under water. The researchers from the University of Liverpool created a genetic family tree of related insect-eating mammals, including hedgehogs and moles.

然而，水鼩為了能吃到在河床和溪床上生活的所有昆蟲幼蟲，不得不到水下覓食。利物浦大學的研究人員們創建了一個有親緣關系的食蟲類哺乳動物的基因家譜，包括刺猬和鼴鼠。

They discovered shrews and moles had evolved the ability to store much more oxygen in their muscles. This allowed water shrews to hold their breath for up to 24 seconds – more than enough time to find all of that hidden aquatic prey.

研究人員們發現，鼩類和鼴鼠進化出了在肌肉中儲存更多氧氣的能力。這使水鼩能夠在水中屏吸長達24秒，足以讓它們尋覓那些隱蔽的水生獵物。

詞匯表

diminutive 極小的，微小的
snouted 有…鼻子的
larvae 幼蟲，單數為 “larva”
driven 驅使
forage 覓食
hedgehogs 刺猬
moles 鼴鼠
evolved 進化了
prey 獵物

閱讀理解：請在讀完上文后，回答下列問題。

1. How much do water shrews weigh?

2. True or false? Water shrews lose heat quickly and burn energy constantly.

3. Which animals mentioned are genetically related to water shrews?

4. How long can water shrews hold their breath for?

答案  

1. How much do water shrews weigh?
Water shrews weigh less than one AA battery.

2. True or false? Water shrews lose heat quickly and burn energy constantly.
True. Water shrews lose heat quickly and burn energy constantly in tiny active muscles.

3. Which animals mentioned are genetically related to water shrews?
Researchers from the University of Liverpool created a genetic family tree of related insect-eating mammals, including hedgehogs and moles.

4. How long can water shrews hold their breath for?
Water shrews can hold their breath for up to 24 seconds.