The bugs which eat oil use oxygen to do so, so slightly lower levels would be a good indicator that they are at work.

菌类在嗜油的时候需要氧气，因此，微小的含氧水平下降就表明菌类正在嗜油。

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The efficiency is a primary evaluating indicator for oil transportation pump.

输油泵的主要评价指标是泵效率。

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Oil-water relative permeability is an important indicator of evaluation of the reservoir, and widely used in reservoir engineering calculation.

油水相对渗透率是评价油藏的一个重要指标，它在油藏工程计算中的应用十分广泛。

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But how much weight will that carry in one of the new General Motors cars whose dashboard indicator urges oil changes as far apart as 15, 000 miles (24, 000 kilometers)?

FORBES: Oreos and lubricants

Oil prices are also a good indicator on investor sentiment regarding the world economy.

FORBES: EU Tuesday "Deal" Seen Taking Another Chunk Out Of Oil Prices

Crude oil may be but one more indicator that the effects of quantitative easing are preemptive, expressing themselves in prices all the way to the announcement, but not necessarily as the policy is being executed.

FORBES: Why Oil Has Fallen Dramatically Since QE3 And Why It Could Drop To $82