Passengers should not unfasten their seatbelts until the captain turns off the sign.

在機長關閉指示燈之前，乘客不應解開安全帶。

Please unfasten the straps on the shipping crate carefully before checking the contents.

檢查內容物之前，請小心解開貨運木箱上的綁帶。

The technician unfastened the back panel of the printer to remove the jammed paper.

技術人員拆開印表機的背板，取出卡住的紙張。