Sills
n. 窗台（板）( sill的复数形式 ); 门槛; 侵入火成岩席; 平巷底
🗣️ 情景例句
OK, Danny.
好啦 ，Danny。
Hush! Talk quietly.
嘘！请小声讲话。
riding on its air cushion over a single rail, which it never touches,at speeds up to 300 m.p.h.----the possibilities appear unlimited.
靠气垫在单轨上行驶而不接触轨道，时速可达每小时300英里。气垫船的前途是不可限量的。