a sudden or disastrous event that destroys or changes a whole region or system
灾难, 大变故
a person, thing, or event that provokes or accelerates change or activity by introducing new perspectives or actions
催化剂, 变革推动者
a large weapon that was used in ancient times to throw stones or other objects with great force
投石机
(geometry) a round 3D shape like a ball that is slightly flattened at the top and bottom points
扁球体, 椭球体
someone who moves from one country to another with the intention of settling there permanently
移民, 移居者
to temporarily stitch two pieces of fabric together with long, loose stitches that can later be easily removed
临时缝合, 做暂时缝合
a fortified structure extending from a wall, typically angled, for defensive purposes
堡垒
an individual, often a leader or authority figure, who possesses the power to create laws, particularly not directly elected by the people
立法者, 法令发布者
someone who can write or approve a law as a member of a legislative body, usually elected by people
立法者, 议员