否則用英語怎么表達

　　例句：

　　1. The dug-outs were secure from everything but a direct hit.

　　除非是直接被擊中，否則這個地下掩體是非常安全的。

　　2. Never force your legs to overstretch, or you can cause injuries.

　　千萬不要迫使雙腿過度拉伸，否則會受傷的。

　　3. He told us to put it right, or else.

　　他讓我們糾正錯誤，否則后果自負。

　　4. The targets would not be achieved unless other departments showed equal commitment.

　　除非其他部門同樣努力，否則這些目標無法達成。

　　5. Training is worthless unless there is proof that it works.

　　除非能證明訓練有效，否則就是白搭。