It will never be entirely flat because of the shape of the crotch seam, so I designed a bag with an elastic opening at the top so it wouldn't be a problem.

它永远不会完全因为裆缝形状扁平的，所以我设计了一个在顶部弹性打开袋子，以便它不会成为一个问题。

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Integral flat head with or without a nozzle attached at the central opening.

中心开孔带或不带接管的整体平盖。

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The opening process of the circle flat parachute with the differential size and the differential vent position of the canopy by the steady flow wind tunnel were dynamic tested.

在改变伞衣面积和透气量的情况下，在定常风洞中对小型平面圆形伞的开伞过程进行了动态试验，研究了开伞过程中伞衣形状和伞衣所受载荷之间的动态关系。

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Stocks were unmoved by the good news, opening flat Thursday morning.

FORBES: Stocks Shrug Off Good Economic Numbers, JP Morgan Among Leaders

The stock index futures were flat ahead of the opening on Wednesday.

FORBES: Bearish Sentiment May Boost Small Caps

There was no sign of that injury in the opening game as the huge, flat forehand that did for Federer in New York earned Del Potro an early break point, but Murray saved it with an ace and then took control.

BBC: Andy Murray beats Del Potro in ATP Finals opener