So don't lose heart whatever you do.

无论做什么，都不要灰心。

Mouse: Oh, Mr. Hare, don't lose heart. Try again!

兔先生，别灰心，再来试一试！咱们来赛一赛！

Don ' t lose heart , we are new to the work after all.

别泄气，这工作对我们来说毕竟是新的。

We don't lose heart, we'll find a way to overcome the difficulty.

只要我们不灰心，我们就能找到克服困难的方法。

Don't lose heart. If you persistent, you will get some fruits.

不要失去信心。只要坚持不懈，就终会有成果。

Although we are suffering such a severe natural disaster, we will eventually overcome the temporary difficulty as long as we don't lose heart.

尽管遭受如此严重的自然灾害，但只要不灰心，我们终会克服暂时的困难。 (Although...)