I must keep my nerve. I must keep my nerve, he said through tight teeth.

“我必须保持镇静，必须保持镇静，”他咬紧牙关说道。

And that means that the nucleus must be intact.

这就意味着细胞核必须保持完整。

So we have to stay vigilant.

所以我们必须保持警惕。

It had to be exactly as it was.

必须保持原声风貌。

So that balance has to be maintained.

因此，必须保持这种衡。

Do you have to be skinny to be a model?

为了当模特必须保持骨感吗？

That room had to stay perfect.

那个房间必须保持完美。

Vigilance is necessary if you want to beat the odds.

如果你想打破常规，必须保持警惕。

You must be sure not to lose your cool.

你必须保持镇定，不能失了风度。

To qualify for the bonus, they must maintain a healthy weight.

要获得奖金，他们必须保持健康。

Students are required to maintain silence in the library.

生在图书馆里必须保持安静。

Thankfully, there is a way out of this trap, but it involves striking a subtle balance.

谢天谢地，还有办法摆脱困境，但是必须保持微妙衡。

The universities are a last line of defense, and must remain that way.

是最后一道防线，必须保持下去。

You have to be in shape.

你必须保持身材。

If you want my help, you have to remain calm.

如果你要我帮忙，就必须保持冷静。

After all, astronauts typically have to be in tip-top shape.

毕竟航天员各方面必须保持最好状态。

No matter how tired we are.

我们都必须保持浪漫感觉。

'I must keep in good health, and not die, ' I replied.

“我必须保持健康，不要死去。”我答道。

But we must be very quiet, or he will take fright and fly away.

但我们必须保持安静，否则他会被惊吓飞走。

He also believed that “liquor must be kept entirely out of politics”.

他也相信“酒类必须保持完全远离政治”。