VOA慢速英语:英国海军潜艇设计看起来像真正的海洋生物

challenge – v. invite a person to compete in a contest or fight

dock – v. join together with another ship

disguise – v. change the appearance of something so it cannot be recognized

dissolve – v. break down or disappear

ambition – n. goal or aim to do or be something

concept – n. an idea of what something could be