You should be cautious when getting involved and test the water before committing yourself.

当你涉足其中时你应该小心谨慎，在表态之前要先行试探。

《柯林斯英汉双解大词典》

To test this, researchers asked 20 people to pick up marbles from water with their hands.

为了测试这一点，研究人员让20人用手从水中捡弹珠。

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The scientist did a test and found that trees can grow because of water and a gas from the air.

科学家做了一个测试，发现树木可以生长，是因为水和空气中的气体。

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While it stands up to rainfall, spillages and the obligatory throw-the-phone-into-a-bowl-of-water test, the device won't function underwater.

ENGADGET: Panasonic Eluga review Mobile

While municipal water utilities are required to provide public reports of test results, bottled-water makers are not. (On the other hand, well water, which is found in many rural areas, isn't regulated as water provided by towns and cities is.) So although you may fork over a pretty penny for bottled water, that doesn't mean it's any better than what's coming out of your faucet.

CNN: Is your bottled water safe?

The U.S. Environmental Protection Agency's drinking-water regulations require that all samples test negative for E.coli.

CNN: Soda fountains contained fecal bacteria, study found