It can be inferred from the first paragraph that .
A.the definition of air pollution will continue to change.
B.water vapor is an air pollutant in localized areas.
C.Most pollutants today can be seen or smelled.
D.a substance becomes an air pollutant only in cities.

Mark the letter A, B, C, or D on your answer sheet to indicate the word whose underlined part differs from the other three in pronunciation in each of the following questions.
A.improves
B.destroys
C.suggests
D.reminds

Mark the letter A, B, C, or D on your answer sheet to indicate the word that differs from the other three in the position of primary stress in each of the following questions.
A.explain
B.involve
C.borrow
D.discuss

Mark the letter A, B, C, or D on your answer sheet to indicate the word that differs from the other three in the position of primary stress in each of the following questions.
A.apartment
B.benefit
C.argument
D.vacancy

Mark the letter A, B, C, or D on your answer sheet to indicate the sentence that best completes each of the following exchanges.
Nancy and James are talking about their school days. - Nancy: "I think school days are the best time of our lives." - James: "______. We had sweet memories together then."A.I'm afraid so
B.Absolutely
C.That's nonsense
D.I doubt it

The word "these" in the second paragraph refers to .
A.the compounds moved to the water or soil
B.the various chemical reactions.
C.the pollutants from the developing Earth
D.the components in biogeochemical cycles.

The word "detectable " is closest in meaning to .
A.special
B.separable
C.beneficial
D.measurable.

Mr. Smith’s new neighbors appear to be very friendly.
A.amicable
B.inapplicable
C.hostile
D.futile

If you are at a loose end this weekend, I will show you round the city.
A.free
B.confident
C.occupied
D.reluctant

They are going to suffer a lot of criticism for increasing bus fare by so much.
A.put across
B.get into
C.stand in with
D.come in for.