I. Arrange the letters in the words in the correct order. Use the words to complete the sentences. One word is extra.
TBIAHAT — __________________ CNEXTIT — ____________________
GGEARBA — _________________ RLEECYCD — __________________
EDOLLUPT — _________________ RONENMEVINT — ______________

1) Scientists say that one species of plant, animal or insect becomes _______________ every day.
2) A lot of trash can be __________________.
3) What can we do to protect the __________________?
4) Every person produces about 650 tons of ______________ during their lifetime.
5) The explosion _______________ the town with dioxin.

II. Choose and circle the correct answer.
1) You may / may not use your mobile phone during the lesson, so will you switch it off, please!
2) Must / Can you hold your breath for more than a minute!
3) You should / had to take your umbrella with you today. The weatherman on the news said there's a storm north of here and it may rain later on this afternoon.
4) He is terribly fat. He may not / should not eat too much.
5) You mustn't / don't have to make any noise here.

III. Choose and circle the letter of the words which correspond to the definitions. An example (1) has been done for you.
1. Making air, rivers etc. dirty.
˅A) Pollution.
B) Waste.
C) Poison.
2. Warming of the atmosphere that occurs when certain gases absorb part of the solar radiation reflected by the Earth.
A) Acid rain.
B) Greenhouse effect.
C) Conservation.
3. The presence in the atmosphere of large quantities of particles or gases produced by human activity; these are harmful to both animal and plant life.
A) Global warming.
B) Air pollution.
C) Smog.
4. Substance causing death or harm if taken by a living thing.
A) Poison.
B) Habitat.
C) Fauna.
5. The science that studies the relations of plants.
A) Ecosphere.
B) Ecology.
C) Astronomy.