authority – n. people who have power to make decisions and enforce rules and laws

delicate – adj. easily broken or damaged

lock – n. an area in a canal or river that has gates at each end which are opened and closed to control the level of the water in different sections of the canal or river as boats move through it

locomotive – n. the vehicle that produces the power that pulls a train

tugboat – n. a small, powerful boat that is used for pulling and pushing ships especially into harbors or up rivers

cargo – n. something that is carried from one place to another by boat, airplane, etc.

positive – adj. good or useful

navigate –v. to find the way to get to a place when you are traveling in a ship, airplane, car, etc.

padding – n. soft material used