Equipped with a flat underside and cupped upper shell that resembles a skewed dome, they are etched with faint concentric lines that recall growth spurts.

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Almost everyone seems to love Cathay Pacific for its smooth service and fantastic Hong Kong hub, but with an 81-inch-long first class bed, flat beds in business class, and shell seats in economy (meaning that even if the person in front of you reclines, their chair-back does not), Cathay's a particularly comfortable option for those who value their personal space.

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Among the largest underlying components of VEU, in trading today BP p.l.c. ( NYSE: BP) is up about 0.6%, Royal Dutch Shell Plc ( NYSE: RDS.A) is trading flat, and GlaxoSmithKline Plc ( NYSE: GSK) is up by about 0.8%.

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"How the sound reflects off this reflecting surface with this composite object on it - which is pretty big and has a cloaking shell on it - really reflects... just like a flat surface does, " Dr Cummer said.

BBC: Acoustic 'cloaking device' shields objects from sound