...unpopular policies, which resulted in social discontent and political instability.

导致社会不满与政治不稳定的不得人心的政策

...Caligula's inherent mental instability.

卡里古拉先天性的精神不稳定

The length of the fuselage was increased due to a degree of directional instability.

由于存在某种程度的航向不稳定性,机身被加长了。