At present the number of the giant lizard is getting fewer and fewer in the world.It is unknown that how many giant lizards of this kind have been alive.

目前世界上的巨蜥数量越来越少，这种巨蜥究竟有多少存活尚不清楚。

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At present the number of the giant lizard is getting fewer and fewer in the world. It is unknown that how many giant lizards of this kind have been alive.

目前世界上的巨蜥数量越来越少，这种巨蜥究竟有多少存活尚不清楚。

youdao

Like most cancers, it is thought to begin in a single cell, with a mutation that is not present at birth but that occurs later for some unknown reason.

我们认为该病与大多数癌症一样，是起源于单个细胞突变，但这种突变并不是先天的，而是发生于后天，但原因不明确。

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Their exact whereabouts are at present unknown.

BBC: Bosnia war: Main players

At present it is unknown what will be unveiled at this event, but we can reasonably assume that it will be toys.

FORBES: Angry Birds To Partner With 'The Force'

Forecasts by Analysys, a British consultancy, suggest that in ten years' time operators may depend on what are at present embryonic or unknown services for two-thirds of their revenue (see chart).

ECONOMIST: Only fakirs need apply