If you have a door in your house, there are at least two hinges.

如果你家里有一扇门，至少有两个铰链。

Each door had two leaves—two hinged leaves for each door.

每扇分两扇，这两扇是折叠的。这边门分两扇，那边门也分两扇。

Two days later, the primary mirror will begin to swing two hinged sections into place to create the complete 6.5-metre-wide mirror.

两天后， 主镜将开始将两个铰接部分摆动到位， 形成完整的 6. 5 米宽镜子。