VOA慢速英语:Great Barrier Reef Choking on Pollutants

assess– v. to make judgment of something

pesticide – n.  a chemical that is used to kill animals or insects that damage plants or crops

pollution – n. substances that make land, water, air, etc., dirty and not safe or suitable to use

environmental -  n. the conditions and influences that affect the growth, health, progress of someone or something

sediment – n. material (such as stones and sand) that is carried into water by water, wind, etc.

chemical –n. a substance (such as an element or compound) that is made by a chemical process

invertebrates – n. a type of animal that does not have a backbone

crustacean – n. a type of animal (such as a crab or lobster) that has several pairs of legs and a body made up of sections that are covered in a hard outer shell

graziers– n. a person who manages land or cattle

runoff –n. water that flows over the surface of the ground into streams

safeguard –v. to protect someone or something