pencil gate

例句：

1. 1. The teacher used a pencil gateto keep the students in their seats.
   老师用一个铅笔门来让学生坐在座位上。
2. 2. The construction workers had to use apencil gate to prevent the heavy equipment fromfalling through.
   建筑工人不得不使用一个铅笔门来防止重型设备掉落。
3. 3. The engineerdesigned a pencil gate to improve airflowin the tunnel.
   工程师设计了一个铅笔门来改善隧道中的气流。