postulate

科学家假设宇宙中存在暗物质来解释观测到的现象。

Scientists ___postulate the existence of dark matter to explain the observed phenomena.

语言学家推测存在一种共同的先祖语言，几十种现代语言都是从它分化而来的。

Linguists ___postulate a common ancestor language from which dozens of modern tongues diverged.

医疗团队决定提出一种罕见的基因突变的假设来解释这些症状的突然出现。

The medical team decided to ___postulate a rare genetic mutation to explain the sudden onset of symptoms.