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they can locate and steer clear of obstacles -- or locate flying insects on which they feed.

并能通過回聲來確定并躲開障礙物，或找到它們賴以為生的昆蟲。

for fear the agents of other firms should be able to trace the kind of research they are likely to be undertaking.

他們生怕別的公司的情報人員據此摸到他們可能要從事的某項科研項目。

A recent article in a weekly newspaper, for instance,

例如，最近一家周報刊登了一篇文章，

its action depends on the surface, water or ground, over which it rides.

它的飛行取決于它所懸浮的水面或地面。

It seems ideal for settlement.

看起來，它很適合居住。

and are capable of a considerable degree of personal affection.

而且會對主人產生相當深厚的私人感情。