But creating such a warhead is the easier part of building a bomb. Harder by far is making the fuel.

然而制造弹头仅仅是核弹研发中比较简单的一步，到目前为止，制造原料要困难得多。

youdao

But for would-be bomb-builders, making the fuel is by far the hardest part.

但对未来的核弹制造者而言，制造燃料是工作中最困难的环节。

youdao

For another, the lack of stabilizing vertical surfaces-a bane of all-wing designs, past and present-resulted in frequent lurches, making sharp shooting and accurate bomb delivery that much harder.

再则缺少提供稳定性的垂直表面是所有全翼设计的致命弱点，过去是，现在也是；——这导致经常侧翻，使快速射击和准确轰炸都变得更为困难。

youdao

He reportedly said he received bomb-making training in the Waziristan area of Pakistan.

VOA: special.2010.05.08

But,according to court documents, Times Square suspect Faisal Shahzad admitted to receiving bomb-making training in the Waziristan region of Pakistan.

VOA: standard.2010.05.05

"You don't have to have access to high levels of al-Qaida or the Taliban to get rudimentary tradecraft and bomb-making training."

VOA: standard.2010.05.18

His role was to provide search and clearance support, uncovering hidden weapons, improvised explosive devices (IEDs) and bomb-making equipment.

BBC: Army sniffer dog Theo given top honour

Both Najibullah Zazi and his attorney denied reports that bomb-making instructions were stored on the suspect's computer.

CNN: Terror suspect: 'Our phone call is being monitored'

No scientist working on India's nuclear programme was under any illusion that bomb-making technology, once learned, could somehow be unlearned.

ECONOMIST: India