conceive

她尝试了多年，但从未成功怀孕。

She had been trying for years, but never managed to ___conceive.

我无法想象出比这日出更美的事物了。

I cannot ___conceive of anything more beautiful than this sunrise.

他们无法想象在那样极端的条件下生存。

They could not ___conceive ___of surviving under such extreme conditions.