否则用英语怎么表达

例句：

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

除非是直接被击中，否则这个地下掩体是非常安全的.。

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

千万不要迫使双腿过度拉伸，否则会受伤的。

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

他让我们纠正错误，否则后果自负。

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

除非其他部门同样努力，否则这些目标无法达成。

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

除非能证明训练有效，否则就是白搭。