When circumstances are favourable, we must not forget that there will still be difficulties.

在顺利的情况下， 要看到还会有困难。

《新英汉大辞典》

Embroidery calls for great care. There must not be even a single sloppy stitch.

刺绣要求很高，一针也不能马虎。

《新英汉大辞典》

And not only food: frequently there must be a beverage.

而且不仅仅为了食物，还常常必须有饮料。

youdao

Fisher notes that not every stutterer in the Drayna study had the defective gene, meaning there must be a number of other genes tied to stuttering.

VOA: standard.2010.02.11

Even though we have a noun, the smile, that if you're not careful might lull you into thinking there must be a thing, the smile.

即使我们有笑容这个名词,如果你不够谨慎,可能会想当然地认为,一定存在着笑容这一事物

耶鲁公开课 - 死亡课程节选

President Obama is said to have stated that, while the past must be understood, he is not there to argue history - and that it is time to "move on" to confront today's challenges.

VOA: standard.2009.04.18

He did the same thing on the other side of my face and then injected the filler into two spots between my eyebrows. (There must not be many nerves there, as he skipped the lidocaine and it didn't hurt.) I was done in less than five minutes.

FORBES: Going Under The Needle

They're carrying banners, they have masks with his face on them, they're chanting, There must be a solution, if not there will be a revolution.

NPR: Obrador Supporters Cry Fraud in Mexican Election

Under the new treaty, arms transfers must not be authorized where there is a major risk the weapons will be used to commit violations of human rights or international humanitarian law, among other risk-assessment criteria, which also include the risk of gender-based violence, diversion and undermining peace and security.

CNN: Syrian arms embargo: Why more weapons to Syria is a mistake