Английский! Будьте добры помогите! Спасибо!
Fill in the gaps with the appropriate form of the words in brackets.

Pollution is the introduction of _____ (HARM) materials into the environment. These materials are called _____ (POLLUTE). They can be natural, such as _____ (VOLCANO) ash or created by human _____ (ACTIVE), such as trash or runoff produced by factories. All these materials damage the quality of air, water, and land. Pollution is a ______ (GLOBE) problem. Urban areas are ______ (USUAL) more polluted than the countryside. Although it may seem ______ (POSSIBILITY), pollution can spread to remote places where no people live. Annually the level of pollution tends to ______ (HIGH).