A closed plane curve resulting from the intersection of a circular cone and a plane cutting completely through it.

由完全相交的一个圆锥体和一个平面的交集所形成的闭合的平面曲线。

youdao

Well, you just take a closed curve in the plane.

只需在区域中取一条封闭曲线。

youdao

Because the airport was closed, the pilot had to land the plane in an open field.

由于机场关闭，飞行员只得将飞机降落到一片旷野里。

youdao

When the door was closed on that plane, I knew we were finally safe, and a wave of overwhelming relief swept throughout my body.

BBC: How I left Zimbabwe

Just before the plane doors closed, a young couple came on with a sleeping baby.

FORBES: Celebrity, Inc.

However, when the U.S. fighters spotted the Iranian plane, they closed to within two miles of the approaching craft.

WSJ: U.S. Fighters Warned Off Iranian Jet